Correct Answer: cock

Solution : The third option is correct.

Cock and bull story is an idiomatic expression that refers to a fabricated or unbelievable tale or explanation.
While fox and wolf are also animals, they do not collocate with the phrase cock and bull story .

Rooster is a term for a male chicken, and in this context, cock is the more commonly used term in the idiomatic expression.

Therefore, the complete sentence is: Some people are in the habit of sharing cock and bull story on unsuitable occasions.