Answer: The answer is C. Hope this helps :)
Explanation:
To test the effectiveness...
A. This variable should be controlled (the same in both groups).
B. The new chemical is what is being added to the experimental group.
C. This is the control group to which the treated couch should be compared.
D. This is the experimental group to which data should be taken.
Final answer: D
After the macrophage fails the Helper T Cell stimulates the B cells (create antibodies) if pathogen is extracellular and Cytotoxic T Cells (killer T cells, release perforin) if pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
<span>Hope that's helpful.</span>
1. Saltwater is completely different from freshwater
2. Only certain animals can live in saltwater/regular water
3. Plants may not require things from saltwater to survive, things can die
