Directions: Choose the alternative which best expresses the meaning of the idiom/phrase (shown in quotes). The two women are so jealous, that at the 'drop of a hat' they start insulting each other.

'At the drop of a hat' means instantly, at the slightest provocation, i.e. without any real reason. The women start insulting each other for no reason at all. The options about a hat falling are literal readings, and 'on every occasion' misses the sense of 'without provocation'.