Peter has $15$ dollars and $80$ cents. Two pencils cost $3.80$ dollars, and one ruler is $70$ cents cheaper than one pencil. After buying one pencil and two rulers, how much does he have left? 
选项为:A:$11.5.$ dollars  B:$10.5.$ dollars  C:$10.8.$ dollars  D:$12.7.$ dollars  E:$9.5.$ dollars  请回答其中一个选项.