Question

Antonyms: Match each word with the word or phrase most nearly its opposite.
11.
coherent

A.
united

B.
lighthearted

C.
confusing

D.
serious

Answer 1

Coherent is opposite to C. CONFUSING.

Coherent means consistent, logical, and orderly. 
Confusing is the opposite of coherent because it means inconsistent, ambiguous, unclear, and highly confusing or bewildering.

Answer 2

Coherent means logical and easy to understand. 
So the antonym would be:
C. Confusing

Hope this helps :)