Correct option is A
The correct antonym of the given word is (a) Feeble.
Puissant: very powerful, strong, or influential; having great strength or authority. (Hindi: शक्तिशाली / प्रभावशाली)
Example: The kingdom had a puissant army that dominated the region.
Feeble: physically weak; lacking strength, power, or effectiveness. (Hindi: दुर्बल / कमजोर)
Example: After the illness, he felt feeble and tired.
Synonyms: mighty, potent, strong, influential.
Antonyms: weak, powerless, frail, ineffectual.
Meanings of all the other given options:
· (b) Robust: strong and healthy; sturdy (Hindi: मजबूत / सुदृढ़)
· (c) Powerful: having great power or strength (Hindi: शक्तिशाली)
· (d) Strong: having strength; not weak (Hindi: मजबूत)