If $P(A)=\Large\frac{4}{5}$,and $P(A\cap B)=\Large\frac{7}{10}$,then P(B|A) is equal to

Question

$\begin{array}{1 1}(A)\;\frac{1}{10}\quad(B)\;\frac{1}{8}\quad(C)\;\frac{7}{8}\quad(D)\;\frac{17}{20}\end{array} $