A body that is initially at rest explodes into two masses $M_1$ and $M_2$. They move away from each other with speeds $v_1$ and $v_2$, respectively. What is the ratio $\frac{v_1}{v_2}$?
- A$\frac{M_1}{M_2}$
- B$\frac{M_2}{M_1}$
- C$\sqrt{\frac{M_1}{M_2}}$
- D$\sqrt{\frac{M_2}{M_1}}$