There are many different categories of T-cells that carry out various roles for the immune system. Differentiation for most T-cells occurs during the T-cell maturation, but some differentiation occurs after maturation following antigen presentation. One type of T-cell's functioning is dependent on antigen presentation and provides the immune system with continued protection against past pathogens. What is this category of T-cell?
A) Helper T
B) Memory T
C) Cytotoxic T
D) Natural Killer T