Question

Which option adds an adjective to the sentence? She sat in the room.

A.She sat in the room quietly.
b.She sat in the yellow room.
C.She patiently satin the room quietly.
D. With her dog, she sat in the room.

Answer 1

B is the correct answer:

Sit is a verb
Quiet is an adjective, but quietly is an adverb
With is a preposition
Room is a noun
Patiently is an adverb

Answer 2

B She sat in the yellow room because 'yellow' modifies 'room' and none of the other choices modify 'room', which is the noun to be modified.