A large sheet carries uniform surface charge density `sigma` . A rod of length 2l has a linear charge density `lambda` on one half and `-lambda` on the second half. The rod is hinged at the midpoint O and makes an angle `theta` with the normal to the sheet. The torque experience by the rod is
A. `(sigma lamdal)/(2 epsilon_(0))`
B. `(sigma lamdal^(2))/(2 epsilon_(0))`
C. `(sigma lamda l^(2))/(epsilon_(0))`
D. `(sigma lamdal)/(epsilon_(0))`
