Which part of speech is the underlined word?

I'm using a ruler to help draw a straight line.

A.
adverb

B.
interjection

C.
adjective

D.
pronoun

underline word: straight

Question

Which part of speech is the underlined word? 

I'm using a ruler to help draw a straight line.
 
 A.
adverb
 
 B.
interjection
 
 C.
adjective
 
 D.
pronoun

underline word: straight

anonymous · Answer

Straight describes the line, yes?
For example, a line could be curvy, wavy, long, etc.
The line is a noun because it is a person, place, or THING.
Which of the following choices describes a noun. (This is like a definition question now. You just need to know what the choices mean/are.)

anonymous · Answer

P
r
o
n
o
u
n