Which words use a prefix that means "not”? Check all that apply. onion
uncover
knotted
nontoxic
undo

Uncover, non toxic,

Explanation:

Uncover- not cover or not to cover

example: anna, uncover the bed !!!

non toxic- not toxic or its not toxic

example: the drink is nontoxic

the un- in the word undo means like reverse so it wouldnt be undo

Note: There are two different prefixes spelled <un>. The first un- means “not, opposite”; the second means “reverse, remove.

i think the answer is c