A certain cell type has existed in the blood and tissue of its vertebrate host's immune system for over twenty years. One day, it recognizes a newly arrived antigen and binds to it, subsequently triggering a secondary immune response in the body. Which of the following cell types most accurately describes this cell?
a. plasma cell
b. thyroid cell
c. memory cell
d. macrophage

c. Memory Cell

Explanation:

Memory cell is a long-lived immune cell that has the capability of recognizing a foreign particle that it has previously encountered and consequently mount a quicker and stronger immune response. Because this cells are able to recognize foreign antigens they have previously encountered hence, the name memory is used.

These cells exist in the blood and tissue of its host's immune system for a very long period of time.

Memory cell are divided into two (2) categories, namely;

a. Memory B cells

b. Memory T cells

Memory B cells produce antibodies triggering a subsequent secondary immune response while Memory T cells do not produce antibodies.

i believe it is the last one. im sorry if im wrong!