I am going to go with either C,A B.
I'm not entirely sure. it's just what i think
This figure illustrates 3 hypotheses of how a cancer stem cell may arise: (1) A stem cell undergoes a mutation, (2) A progenitor cell undergoes two or more mutations, or (3) A fully differentiated cell undergoes several mutations that drive it back to a stem-like state.
After the macrophage fails the Helper T Cell stimulates the B cells if pathogen is extracellular and Cytotoxic T Cells if the pathogen is intracellular. Once the pathogen is killed the B Cells create Memory B Cells and the Killer T Cells create memory T Cells.
Group of people could have a very specific challenge having to do with the person or the task - need to watch the same person to see how they change; Ex: some type of physical or cognitive challenge and want to see their progression
Hope this helps