The drugs were innocuous and had no side effect.

A. effective

B. harmless

C. imported

D. discovered

Answer: Option B

Solution(By Examveda Team)

Effective : successful in producing a desired or intended result.
Harmless : not able or likely to cause harm.
Imported : (of goods or services) brought into a country from abroad for sale.
Discovered : find unexpectedly or during a search.
Innocuous : not harmful or offensive.

Synonym of Innocuous is Harmless