A company has a small network, consisting of a single switch and a single router. The switch has been configured with two VLANs, and route-on-a-stick is being configured on the router for Inter-VLAN routing. A trunk is configured to connect the switch to the router. What is the minimum number of router subinterfaces that are required for all the VLANs to communicate?

A.
one

B.
three

C.
two

D.
zero