A small body b starts from rest at the hightest point A of a large fixed sphere , with centre C ,and slides down with a small but constant speed , then ,the coefficent of friction between B and the sphere ,at any point P on the surface of the sphere such that
`angle ACP=theta,` must be equal to
A. `sin theta`
B. `costheta`
C. `tantheta`
D. `|costheta-sintheta|`
