In response to foreign organisms, humans produce a variety of antibodies that can bind to the organism. In the production of human antibodies, which one of the following can cause the production of different proteins from a single gene?
A.
Pretranscription processing of hnRNA
B.
Removal of introns from hnRNA
C.
Addition of a cap to the 5 ′ -end of hnRNA
D.
Addition of a cap to the 3 ′ -end of hnRNA
E.
Alternative sites for synthesizing the poly(A) tail