Synonym of HARBINGER

Answer: Option D

Pilot : a person who operates the flying controls of an aircraft.
Forerunner : a person or thing that precedes the coming or development of someone or something else.
Steward : a person employed to look after the passengers on a ship, aircraft, or train.
Messenger : a person who carries a message or is employed to carry messages.
Harbinger : a person or thing that announces or signals the approach of another.

Synonym of Harbinger is Messenger