Answer:
The correct option is : c. Plasmodium
Step-by-step explanation:
Antigenic variation is a mechanism in which pathogens alter the carbohydrates or proteins present on their surface, to gain immunity from the immune system of the host. This also allows the pathogen to re-infect the previously infected hosts.
Example: The protozoan parasite, Plasmodium falciparum undergoes antigenic variation.