B) is the correct answer. The flu virus does not have the same genetic makeup each year as with each individual it infects its rapidly mutating.
Answer:
Because the vaccine is an antigen from living, weakened or killed microorganisms that activate the immune system and the body produces protective antibodies.
Answer:
A.
Explanation:
A parasite does not feed it's host; in fact, it takes food energy/ food from it's host.