A block of mass M is pulled along a horizontal frictionless surface by a rope of mass m. If a force P is applied at the free end of the rope, the force exerted by the rope on the block will be [CBSE PMT 1993; CPMT 1972, 75, 82; MP PMT 1996; AIEEE 2003]

• A.                              P                     
• B.                         \[\frac{Pm}{M+m}\]            
• C.                         \[\frac{PM}{M+m}\]            
• D.                           \[\frac{Pm}{M-m}\]