Mighty :

A. Forcible

B. Forceful

C. Weak

D. Tough

E. Haughty

Answer: Option C

Solution(By Examveda Team)

Forcible : done by force.
Forceful : strong and assertive, vigorous and powerful.
Tough : strong enough to withstand adverse conditions or rough handling.
Haughty : arrogant or conceited
Mighty : possessing great and impressive power or strength.

So, opposite of Mighty is Weak.