A sphere of mass m moving with velocity v enters, a hanging bag of sand and stops. If the mass of bag is M and it is raised by height h, then the velocity of sphere was

Question

$$(a)\;\frac{M+m}{m} \sqrt {2gh} \quad (b)\;\frac{M}{m} \sqrt {2gh} \quad (c)\;\frac{m}{M+m} \sqrt {2gh} \quad (d)\;\frac{m}{M} \sqrt {2gh}$$