$A$ bag of mass $M$ is suspended by a long string. $A$ bullet of mass $m$ moving with velocity $v$ hits the bag and gets embedded in it. For the (bag + bullet) system:

• A
  The momentum is $\frac{mvM}{M + m}$.
• B
  The kinetic energy is $\frac{mv^2}{2}$.
• C
  The momentum is $\frac{mv(M + m)}{M}$.
• D
  The kinetic energy is $\frac{m^2v^2}{2(M + m)}$.