A block of mass m is in contact with the cart C as shown in figure :– The coefficient of static friction between the block and the cart is $\mu$. The acceleration $\alpha$ of the cart that will prevent the block from falling satisfies –

Question

( A ) $\alpha\geq\frac{g}{\mu}$
( B ) $\alpha>\frac{mg}{\mu}$
( C ) $\alpha>\frac{g}{\mu m}$
( D ) $\alpha<\frac{g}{\mu}$</span>