He was adjudged as the best orator of the college.

Answer: Option D

Critic : a person who expresses an unfavourable opinion of something.
Debater : a person who argues about a subject, especially in a formal manner.
Singer : a person who sings, especially professionally.
Speaker : a person who delivers a speech or lecture.
Orator : a public speaker, especially one who is eloquent or skilled.

Synonym of Orator is Speaker