Answer:
Negate.
Step-by-step explanation:
The word "negate" means to "nullify; make ineffective."
Meanwhile, the word "nurture" means to "care for and encourage the growth or development of."
and "benign" is "gentle and kindly."
Both of these words have positive connotations and don't mean something that cancels out nor something that denies the truth of something.
The word "negate" is your answer.
Hope this helped! :) <3