Discovered :

A. Exposed

B. Revealed

C. Concealed

D. Contended

Answer: Option C

Solution(By Examveda Team)

Discovered : find unexpectedly or during a search.
Exposed : make (something) visible by uncovering it.

Revealed : make (previously unknown or secret information) known to others.
Concealed : kept secret, hidden


Contended : struggle to surmount (a difficulty).


Thus, antonym of Discovered is Concealed.