a uniform solid cylinder of mass M and radius R is pulled horizontally by a force F acting at its centre of mass from rest.Then indicate the correct direction of friction assuming that it rolls without sliding on a rough horizontal surface? plz answer with a complete explanation...i will approve..!

See initially, the acceleration on the lowest point is in the right direction. So to avoid sliding, friction need to act in the left direction, so as a=r(alpha). This is the case when there is no sliding on the rough surface.

answer for ur question is (a)

friction always tries to stop relative motion.here at the contact, the given force is trying to move forward,so friction force will act backward.

the ans z (b)
coz the pt of contact body with the ground tries to move backward(left) 
and as frition this state of motion it just acts forward
for reference u can c ashish arora's buk