Visualization of B-Cell Traffic Between the Light and Dark Zones

Visualization of B-cell traffic between the light and dark zones of the germinal center has shown that they migrate far less than had been predicted.This demonstrates that

A) the traditional model of trafficking is inaccurate.
B) the rate of hypermutation and selection does not require extensive movement.
C) only brief contacts by the B cells with helper T cells are needed.
D) both the traditional model of trafficking is inaccurate and only brief contacts by the B cells with helper T cells are needed.
E) both the rate of hypermutation and selection does not require extensive movement and only brief contacts by the B cells with helper T cells are needed.