Malaria is caused by Plasmodium falciparum, a non-motile protist that contains a cluster of microtubules at one end of the cell. Once injected into the blood stream, these microtubules are used to attach to red blood cells. Plasmodium falciparum is which of the following?
a. A protozoa.
b. An algae.
c. A slime mold.
d. A diatom.
e. An apicomplexan.