Assume that the number of B cells producing a specific antibody is proportional to the concentration of that antibody. On day 16, assume that one out of every 105 B cells in the body is specific for antigen A and that the antibody concentration on day 16 is about 2 × 101. Calculate the frequency of B cells specific for antigen A on day 36 if the antibody concentration on day 36 is about 8 × 103.
A) 1 in 105.
B) 1 in 400.
C) 1 in 250.
D) 1 in 20.