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 "remove" or "reduce". "Congestant" relates to congestion. So "decongestant" likely means something that reduces congestion. The context of sinus pain and nasal pressure (symptoms of congestion) further supports this. A doctor offering it would be for relief (reducing congestion), not causing, defining, or measuring it.

Answer:

a substance that reduces congestion