Differentiate Between Antigenic Drift and Antigenic Shift,and Select the True

Differentiate between antigenic drift and antigenic shift,and select the true statement.

A) Small changes in viral surface proteins are known as an antigenic drift and result in decreased vaccine effectiveness. When the virus undergoes a major change in its surface proteins such as hemagglutinin and neuraminidase, this is considered an antigenic shift.
B) Small changes in viral surface proteins are known as an antigenic shift and result in decreased vaccine effectiveness. When the virus undergoes a major change in its surface proteins such as hemagglutinin and neuraminidase, this is considered an antigenic drift.
C) Antigenic drift can prevent the antibody from recognizing the organism if exposure reoccurs.
D) None of these are correct.