Ryan, Jillian, and Maria met for an hour to discuss the current parking problem at Big University. Ryan kept cracking jokes and wouldn't take the topic seriously. Jillian tended to provide substantive information regarding the situation whereas Maria tended to be very process oriented. The notion that they gravitated toward certain roles during group interaction reflects what systems concept?

A. integration
B. equifinality
C. differentiation
D. dynamic equilibrium

C. differentiation