Which is the closest antonym for the word avid?

The closest antonym for avid is apathetic.

C. she has experienced a learned taste aversion, which can occur after only one pairing of food and illness.

Explanation:Taste aversion is a term used to describe the learned response to the taste of a spoilt food, learned response causes persons who experience it to avoid and prevent eating foods related to the food that caused the taste aversion.

The ill feelings of Margo due to the smell of fried chicken is a result of Learned response to a particular taste which Margo has of fried chicken which must have been associated with Margo tasting or eating rotten or spoilt chicken previously.