Explanation:

- The phrase "ring a bell" is commonly used to convey the idea of something sounding familiar or being recognizable, often sparking a recollection or memory.

- Option 1: To sound familiar. This is the correct meaning of the idiom.

- Option 2: To be very frightened. This describes someone feeling scared or terrified, which doesn't relate to the meaning of the idiom.

- Option 3: To take advantage. This suggests exploiting or benefiting from something or someone, unrelated to the idiom's meaning.

- Option 4: To mock someone. This means to ridicule or make fun of someone, which is also unrelated to the idiom's meaning.