Step 1: Understanding the Question:
We must identify the part of speech of the word "continuously" in the provided sentence.
Step 2: Detailed Explanation:
Let us analyze the sentence structure to see what the word "continuously" is modifying.
"It" serves as a dummy subject pronoun for the weather condition.
"has rained" is the main verb phrase in the present perfect tense.
The word "continuously" is placed immediately after the verb phrase.
It answers the question: *How* did it rain? It rained without stopping.
In English grammar, words that modify verbs, adjectives, or other adverbs are known as adverbs.
Adverbs typically answer questions like how, when, where, or to what degree an action was performed.
Specifically, "continuously" is an adverb of manner.
Let us evaluate the incorrect options:
(A) adjective: modifies a noun. "Continuously" does not describe the pronoun "It", it describes the action of raining.
(C) conjunction: connects clauses. It does not connect anything here.
(D) preposition: shows relationships between nouns. Not applicable here.
(E) interjection: expresses strong emotion (like "Wow!"). Not applicable here.
Therefore, the correct part of speech is an adverb.