Right knowledge is a (strong) instrument for moulding the character of the young.

Options

A. powerful
B. potent
C. striking
D. No Improvement

Answer

A

Explanation

powerful (Adjective) : having a lot of strength or force: having a great effect.
Look at the sentences :
• She must be very strong to carry such a weight on her back.
• His speech about cruelty to children was very powerful.
Here, powerful is the right usage.