Putting these lines~$\left\textbar{} \right\textbar$ round a number or calculation makes sure the answer is positive; for example both $\left\textbar{} 8\right\textbar$~and $\left\textbar{} -8\right\textbar$~ would give the answer $8$.What is the answer to:$10-\left\textbar{} 4-20\right\textbar$ 
选项为:A:$$4$$  B:$$26$$  C:$$-6$$  D:$$6$$  请回答其中一个选项.