VFR minima Class C : 3 SM visibility and 500' below, 1000' above and 2000' lateral distance from cloud. Class C radar service provides Traffic advisories to VFR traffic.
VFR minima Class B : 3 SM visibility and clear of cloud. Class B provides separation to VFR traffic.
Therefore you only need the 3 SM visibility in order to be able to visually navigate, you do not need the cloud clearance requirements to see and avoid other traffic as you would in C,D and E airspace.