Frugal :

A. Extravagant

B. Rich

C. Miserable

D. Happy

Answer: Option A

Solution(By Examveda Team)

Rich : having a great deal of money or assets, wealthy.
Miserable : wretchedly unhappy or uncomfortable.
Happy : feeling or showing pleasure or contentment.
Extravagant : lacking restraint in spending money or using resources.
Frugal : sparing or economical as regards money or food, thrifty, prudent.

Antonym of Frugal is Extravagant.