Step 1: Understanding the Concept:
The fundamental objective of this literary question is to distinguish the specific figure of speech known as a metaphor from other common figurative devices such as similes and personification.
A metaphor is a trope that establishes a direct relationship of identity between two unrelated subjects by stating that one thing literally is the other, thereby transferring the qualities of the second object (the vehicle) onto the first (the tenor).
This device is a cornerstone of English literature because it allows for condensed, powerful imagery that transcends literal descriptions, forcing the reader to find commonality between disparate concepts.
Step 2: Detailed Explanation:
To provide a comprehensive analysis, we must examine the internal logic and linguistic markers present in each of the four provided sentences to determine their classification.
Detailed Analysis of Option (A): "Life is a journey."
In this classic example, the abstract concept of human existence ("life") is directly equated with a physical voyage ("journey").
The sentence does not suggest that life is "similar to" or "reminiscent of" a journey; it uses the copula verb "is" to assert a total merger of the two concepts.
By doing so, the author implies that life has a distinct path, obstacles, travelers, and an eventual destination.
Because this comparison is established without the use of comparative words such as "like" or "as," it is a quintessential metaphor.
Linguistically, "life" acts as the tenor (the thing being described) and "journey" acts as the vehicle (the image carrying the meaning).
Detailed Analysis of Option (B): "He fought like a tiger."
This sentence compares a human subject's fighting ability to the predatory ferocity of a tiger.
Crucially, the presence of the comparative word "like" acts as a linguistic barrier that prevents the two concepts from merging into a single identity.
This structure defines a simile rather than a metaphor.
In a simile, the comparison is made explicit and external, suggesting a resemblance rather than an inherent identity.
Consequently, while it is a figure of speech, it does not meet the criteria for a metaphor.
Detailed Analysis of Option (C): "The classroom was a zoo."
Here, a physical environment associated with learning and discipline is equated with a place containing wild, unrestrained animals.
The usage of "was" (the past tense of 'to be') establishes a direct metaphor.
The author uses this device to emphasize the chaos, noise, and lack of order within the classroom.
Like Option (A), there are no comparative markers like "as" or "like."
The classroom is not "like" a zoo; for the sake of the imagery, the classroom "is" the zoo.
This makes it a definitive and highly effective metaphor.
Detailed Analysis of Option (D): "The stars danced in the sky."
This sentence attributes a human physical action ("danced") to inanimate celestial objects ("stars").
This is the hallmark of personification, which is the practice of giving human characteristics to non-human entities.
While it is an imaginative comparison, it lacks the two-part object-to-object comparison structure required for a metaphor.
The stars are not being compared to dancers; they are simply performing a dancer's action.
Therefore, it is categorized as personification and is incorrect for this specific question.
Step 3: Final Answer:
Upon rigorous analysis of the linguistic structure, we find that both sentences (A) and (C) establish a direct relationship of identity without comparative words.
Thus, the correct metaphors are (A) "Life is a journey" and (C) "The classroom was a zoo."