Judy draws a plan of her bedroom using a scale of $$2\text{cm}$$ to $$7\text{m}$$.  On the plan, the playground is $$10\text{cm}$$ long.  What is the real length of the playground? 
选项为:A:$$5\text{m}$$  B:$$20 \text{m}$$  C:$$35\text{m}$$  D:$$70 \text{m}$$  E:$$55\text{m}$$  请回答其中一个选项.