Answer
(b).
Work Step by Step
$\hat{p_1}=\frac{x_1}{n_1}=\frac{459}{573}\approx0.801$
$\hat{p_2}=\frac{x_2}{n_2}=\frac{552}{719}\approx0.768$
Thus $\hat{p_p}=\frac{x_1+x_2}{n_1+n_2}=\frac{459+552}{573+719}\approx0.783$
Thus the answer is (b).