ALERT

A. Energetic

B. Observant

C. Intelligent

D. Watchful

Answer: Option D

Solution(By Examveda Team)

Energetic : showing or involving great activity or vitality.
Observant : quick to notice or perceive things.
Intelligent : having or showing intelligence, especially of a high level.
Watchful : watching someone or something closely; alert and vigilant.
Alert : quick to notice any unusual and potentially dangerous or difficult circumstances; vigilant.


Synonym of Alert is Watchful