Two objects of mass $10\text{kg}$ and $20\text{kg}$ respectively are connected to the two ends of a rigid rod of length $10\text{m}$ with negligible mass. The distance of the center of mass of the system from the $10\text{kg}$ mass is:

1. A
   $\frac{10}{3}\text{m}$
2. B
   $\frac{20}{3}\text{m}$
3. C
   $10\text{m}$
4. D
   $5\text{m}$