What is a requirement to operate GPUs in a Dell EMC PowerEdge R740 server?

What is a requirement to operate GPUs in a Dell EMC PowerEdge R740 server?
A . All GPU cards must be installed at the same time
B . All GPU cards must be of the same type but can be a different model
C . All GPU cards must be of the same type and model
D . All GPU cards must be installed on the same riser card

Answer: C