A US Emergency Relief Agency Is Considering Sending a Team of of Experts

A U.S. emergency relief agency is considering sending a team of experts to another country to treat a severely contagious disease outbreak. Each team member is paid $10,000 for this one-week-long job. The agency estimates effectiveness as follows:
? $\begin{array}{|l|l|}\hline \text { Number of Team Members }& \text { Number of Deaths }\\\hline 0 & 1,000 \\\hline 5 & 400 \\\hline 10 & 150 \\\hline 15 & 30 \\\hline 20 & 30 \\\hline\end{array}$
-Diminishing marginal returns sets in with

A) the team of size 5.
B) the team of size 10.
C) the team of size 15.
D) the team of size 20.
E) does not occur.