he soldier displayed exceptional courage and saved Major from the enemy's hand.

A. avoidable

B. unusual

C. strange

D. abnormal

Answer: Option B

Solution(By Examveda Team)

avoidable : able to be avoided or prevented.
unusual : not habitually or commonly occurring or done.
strange : difficult to understand or explain.
abnormal : deviating from what is normal or usual, typically in a way that is undesirable or worrying.
exceptional : unusual; not typical.

Synonym of exceptional is unusual