After each of the following sentences, a list of possible interpretations is given. Choose the interpretation…

Analyze the question: The sentence uses the idiom "cocked their ears." You are asked what it means to listen in this way.

Explain the concept: To "cock one's ear" (or "prick up one's ears") comes from the behaviour of animals like dogs and horses. They tilt or raise their ears when they hear something and want to catch every sound. So the idiom means to listen carefully, eagerly and with full attention.

Step-by-step solution:

1. A. no understanding - The idiom says nothing about comprehension. It describes how attentively someone listens. Wrong.
2. B. rapt attention - "Rapt" means completely absorbed. This matches the idea of listening very closely. Correct.
3. C. no interest - This is the opposite of the idiom. Wrong.
4. D. little interest - This is also the opposite. Someone who cocks their ears is very interested, not slightly interested. Wrong.

Answer: B. rapt attention

Tip: For idiom questions, picture the literal image. Ears raised and tilted means the listener is alert and focused. Related idioms to remember are "prick up one's ears" (suddenly pay attention) and "lend an ear" (listen).