Review of Related Disease (RRD) 4 Practice Exam

Memory B-cells provide lasting immune memory and drive a faster, stronger response when the same microbe is encountered again. After the first exposure, some B cells become memory cells that linger for years and remember the antigen. When re-exposed, these memory cells rapidly react, proliferate, and differentiate into antibody-secreting plasma cells, producing high-affinity antibodies quickly. This creates a quicker and more robust secondary immune response.

The other statements don’t fit because memory B-cells themselves aren’t the cells that produce antibodies during the very first encounter (that’s the job of plasma cells formed during the primary response). They also don’t differentiate into plasma cells only during the initial exposure; they differentiate into plasma cells upon re-exposure. And memory B-cells are part of the adaptive immune system, not the innate.