A Nurse Is Explaining How the Humoral and Cellular Immune $\mathrm{T}$

A nurse is explaining how the humoral and cellular immune responses should be seen as interacting parts of the broader immune system rather than as independent and unrelated processes. What aspect of immune function best demonstrates this?

A) The movement of B cells in and out of lymph nodes
B) The interactions that occur between $\mathrm{T}$ cells and $\mathrm{B}$ cells
C) The differentiation between different types of $\mathrm{T}$ cells
D) The universal role of the complement system