He kept his eyes peeled and his ears pricked for some important clue.

A. hint

B. notable

C. remarkable

D. sensational

Answer: Option A

Solution(By Examveda Team)

Hint : a slight or indirect indication or suggestion.
Notable : worthy of attention or notice; remarkable.
Remarkable : worthy of attention; striking.
Sensational : causing great public interest and excitement.
Clue : a piece of evidence or information used in the detection of a crime.

Synonym of Clue is Hint