Question

when would an rh - negative person make antibodies to the rh antigen?
a at birth
b when exposed to rh factor
c an rh - negative person will never get antibodies

Explanation:

The immune system produces antibodies when exposed to foreign antigens. The Rh factor is an antigen. An Rh - negative person does not have the Rh antigen on their red blood cells. When an Rh - negative person is exposed to the Rh factor (e.g., during pregnancy with an Rh - positive fetus or through a blood transfusion of Rh - positive blood), their immune system recognizes it as foreign and mounts an immune response by producing antibodies against the Rh antigen. At birth, there is no prior exposure (unless there was a specific event during birth involving Rh - positive blood exposure, but generally, it's the exposure to the Rh factor that triggers antibody production). And it's not true that an Rh - negative person will never get antibodies; exposure to Rh factor can cause antibody production.

Answer:

B. When exposed to Rh factor