Question

why are marine scientists particularly concerned about parasites in the blue crab population?
a. blue crabs play an important role in the regions economy.
b. blue crabs should have evolved the ability to resist infection.
c. the parasites migrate with the blue crabs and spread to other species easily.
d. the parasites are deadly to the humans that eat blue crabs.

Explanation:

Blue crabs are economically significant. Their role in the economy (e.g., fishing industry) makes parasites in their population a concern. Option B about evolving resistance is not a main concern. Option C about parasite spread to other species is less relevant than economic impact. Option D about parasites being deadly to humans is not a typical main reason for marine scientists' concern compared to economic aspects.

Answer:

A. Blue crabs play an important role in the region's economy.