Figure 45-1 Use the Figure to Answer the Corresponding Question(s)

Figure 45-1
Use the figure to answer the corresponding question(s) .
-Based on the graph in Figure 45-1, which of the following statements is true?

A) The primary response to the initial injection subsided after seven weeks.
B) The primary response to the initial injection peaked at 10² antibody units.
C) The primary response to the initial injection was faster, but not as intense as the secondary response.
D) The secondary response to the initial antigen was both faster and more intense than the primary response.
E) The primary and secondary responses to the initial antigen were about equal.