A particle is projected with speed `u` at angle `theta` to the horizontal. Find the radius of curvature at highest point of its trajectory
A. `(u^(@)cos^(2)theta)/(2g)`
B. `(sqrt(3)u^(2)cos^(2)theta)/(2g)`
C. `(u^(2)cos^(2)theta)/(g)`
D. `(sqrt(3)u^(2)cos^(2)theta)/(g)`