A Child Is Infected with a Virus,mounts Antibody Responses to a Viral

A child is infected with a virus,mounts antibody responses to a viral protein,and recovers.One year later,the child is exposed to the same type of virus,and mounts a memory response specific to the same viral protein.Which one of the following statements comparing the (primary) antibody response to the viral protein and the memory response a year later is true?

A) The antibodies in primary responses were of highrt affinity for viral protein than those produced in memory responses.
B) The peak blood levels of antibodies during the primary response was higher than in the memory response.
C) T follicular helper (Tfh) were mainly required during the memory response,and not in the primary response.
D) Antibodies specific for the viral protein were only produced by plasma cells in the memory response.
E) In the primary response,mainly IgG was produced,whereas in the memory responses mainly IgM was produced.