During a cell-mediated immune response, which of the following describes how infected cells are detected by the immune system?

a
The infected cell's membrane shows some of the antigens of the invading pathogen.

b
The pathogen engulfs and destroys healthy cells, leaving antigens behind.

c
Antibodies bind with the pathogen's antigens, causing inflammation and swelling.

d
Memory B cells recognize the cell shape that results from infection by specific pathogens.