Question

read the sentence
when i told the doctor of my sinus pain and nasal pressure, she offered me a decongestant.
based on the prefix, de-, what does the word “decongestant” mean?
a device that causes congestion
a resource that defines congestion
a way to measure congestion
a substance that reduces congestion

Explanation:

The prefix "de -" often means "removing" or "reversing". A decongestant is related to congestion. So it is a substance that reduces congestion.

Answer:

D. a substance that reduces congestion