question_answer

Simplify: \[1-1\div \left\{ 1+1\div \left( 1+\frac{1}{3} \right) \right\}\]

A) \[\frac{3}{7}\]              

B) \[\frac{11}{7}\]

C) \[\frac{7}{3}\]              

D) \[\frac{7}{11}\]

E) None of these