Step 1: Understanding the Concept:
This question asks for the meaning of the idiom "a snake in the grass". We need to find the correct figurative meaning among the given options.
Step 2: Key Formula or Approach:
The idiom "a snake in the grass" refers to a treacherous or deceitful person who pretends to be a friend. The imagery is of a hidden danger (a snake) that cannot be easily seen (it's in the grass).
Step 3: Detailed Explanation:
The sentence states, "She has proved to be a snake in the grass."
- (A) Very poisonous snake: This is a literal interpretation. Idioms are figurative.
- (B) a secret agent: While a secret agent might be deceitful, the idiom is more general and refers to a hidden enemy in any context, usually a personal one, not necessarily espionage.
- (C) an unrecognizable enemy: This captures the essence of the idiom. It refers to someone who appears to be friendly but is secretly an enemy; their treacherous nature is hidden or "unrecognizable" at first.
- (D) not a religious person: This is completely unrelated to the meaning of the idiom.
The best description of a "snake in the grass" is a hidden or secret enemy, someone you can't recognize as a foe.
Step 4: Final Answer:
The meaning of 'a snake in the grass' is an unrecognizable enemy. This corresponds to option (C).