A block of mass M placed on a frictionless horizontal table is pulled by another block of mass m hanging vertically by a massless string passing over a frictionless pully. The tension in the string is

Q: A block of mass M placed on a frictionless horizontal table is pulled by another block of mass m hanging vertically by a massless string passing over a frictionless pully. The tension in the string is

(a) $\displaystyle \frac{m}{M + m} g $

(b) $\displaystyle \frac{M}{M + m} g $

(c) $\displaystyle \frac{M + m}{M m} g $

(d) $\displaystyle \frac{M m}{M + m} g $