If $6\text{cm}$ represents $50\text{km}$ on a map and the actual distance between two towns is $125\text{km}$, then their distance apart on the map is ． 
选项为:A:$8\text{cm}$  B:$10\text{cm}$  C:$15\text{cm}$  D:$18\text{cm}$  E:$12\text{cm}$  请回答其中一个选项.