The term agglutination is defined as a:

A) reduction of red blood cells.
B) condition where erythrocytes are unequal in size.
C) process of clumping together.
D) potentially fatal infection.

Agglutination

The clumping together of particles, typically cells or proteins, that occurs when an antigen is mixed with its corresponding antibody.

Erythrocytes

Red blood cells responsible for carrying oxygen and carbon dioxide throughout the body.