An elevator accelrates upward at a constant rate. A uniform string of length L and mass m supports a small block of mass M that hangs from the celling of the elevator. The tension at distance l from the celling is T. the accelration of the elegvator is
A. `(T)/(M+m-ml//L)-g`
B. `(T)/(2M+m-ml//L)+g`
C. `(T)/(M+ml//L)-g`
D. `(T)/(2M-m+ml//L)-g`