Select the correct statement about the immune system. a. adaptive immunity is characteristic of invertebrates and vertebrates. b. all antigen receptors produced by a single b or t cell are identical and bind to the same epitope. c. antibodies are secreted by t cells.

B. All antigen receptors produced by a single B or T cell are identical and bind to the same epitope.

Explanation:

Antigen receptors are antibody protein anchored to the B-cell membrane.

They are all identical when the antigen receptors is located on one type of B cell making Binding between the receptor and epitope to occur since its structures are complementary. It's not identical when the antigen receptors is located on different types of B cell

c

explanation:

b. lithosphere, asthenosphere, mesosphere   is the answer most likely