If D1 and D2 be the diameters of driver and driven pulleys, then belt speed is proportional to__________________?
A. D1/D2
B. D2/D1
C. D1-D2.
D. D1
E. D1+D2
If D1 and D2 be the diameters of driver and driven pulleys, then belt speed is proportional to__________________?