There was nothing casual about my father's interests.

A. ordinary

B. incidental

C. funny

D. accidental

Answer: Option A

Solution(By Examveda Team)

Ordinary : with no special or distinctive features; normal.
Incidental : happening as a minor accompaniment to something else.
Funny : causing laughter or amusement; humorous.
Accidental : happening by chance, unintentionally, or unexpectedly.
Casual : happening by chance; accidental.

Synonym of Casual is Accidental