Answer
(b)
Work Step by Step
The sample proportion is the number of successes divided by the sample size: $\hat{p}=\frac{x}{n}=\frac{225}{757}\approx0.297$
The z-value belonging to the $90\%$ confidence interval according to the table is $z=1.645$, thus the confidence interval is: $\hat{p}\pm z\sqrt{\frac{p(1-p)}{n}}$, which here is: $0.297\pm 1.645\sqrt{\frac{0.297\cdot(1-0.297)}{757}}$, thus the confidence interval is: $(0.27,0.326)$, thus the answer is (b).