Which of the following antiviral medications prevents viral fusion with host cell membrane?

Maraviroc is aCCR5 coreceptor antagonistthat blocks the receptor site the HIV virus needs to interact with in order to enter the cell.It prevents viral fusion with host cell membrane by binding to the CCR5 receptor on CD4+ T cells and macrophages.

Choice B is wrong becauseAbacavir is wrong because it is anucleoside reverse transcriptase inhibitor (NRTI)that inhibits the enzyme reverse transcriptase, which converts viral RNA into DNA.

It does not prevent viral fusion with host cell membrane.

Choice C is wrong becauseDarunavir is wrong because it is aprotease inhibitor (PI)that inhibits the enzyme protease, which cleaves viral proteins into functional units.

It does not prevent viral fusion with host cell membrane.

Choice D is wrong becauseFosamprenavir is wrong because it is also aprotease inhibitor (PI)that inhibits the enzyme protease.

It does not prevent viral fusion with host cell membrane.

They are effective against a few types of organisms.Narrow spectrum antibiotics are antibiotics that work against a limited range of bacteria, usually either gram-positive or gram-negative.They are more specific and less likely to cause resistance or disrupt the normal flora.

Choice A) They are effective against gram-positive bacteria only.This is not true because some narrow spectrum antibiotics can also target gram-negative bacteria, such as aminoglycosides.

Choice B) They are effective against gram-negative bacteria only.This is not true because some narrow spectrum antibiotics can also target gram-positive bacteria, such as vancomycin.

Choice C) They are effective against one type of organism.This is too restrictive because narrow spectrum antibiotics can work against more than one type of organism, such as penicillins that target both streptococci and staphylococci.