An object, initially at rest, bursts into two masses $M_1$ and $M_2$, which move in opposite directions with speeds $v_1$ and $v_2$ respectively. What is the ratio $\dfrac{v_1}{v_2}$?
- A$\dfrac{M_1}{M_2}$
- B$\dfrac{M_2}{M_1}$
- C$\sqrt{\dfrac{M_1}{M_2}}$
- D$\sqrt{\dfrac{M_2}{M_1}}$