Not conforming to ordinary rules of behaviour

A. Lunatic

B. Absurd

C. Eccentric

D. Maniacal

Answer: Option C

Solution(By Examveda Team)

One word substitute is Eccentric.

Lunatic: a person who is mentally ill (not in technical use).
Absurd: wildly unreasonable, illogical, or inappropriate.
Eccentric: (of a person or their behaviour) unconventional and slightly strange.
Maniacal: exhibiting extremely wild or violent behaviour.