He has enrolled himself to an elementary course in computer.

A. secondary

B. tough

C. advanced

D. simple

Answer: Option C

Solution(By Examveda Team)

Elementary : of the most basic kind.
Secondary : coming after, less important than, or resulting from someone or something else that is primary.
Tough : (of a substance or object) strong enough to withstand adverse conditions or rough handling.
Advanced : new and not yet generally accepted.
Simple : easily understood or done; presenting no difficulty.

Antonym of Elementary is Advanced