Answer:
c. prevent the onset of the primary immune response.
Step-by-step explanation:
In vertebrates , the IgM is produced by the body of vertebrates . It is mainly responsible for the primary immunity of the body , The mutations in the IgM gene leads to some alterations of the primary immunity .
But , the synthesis of B cells are controlled by bone marrow along with the IgH .
The B cells control the Macrophages stimulation of the antigens .