The standard error can be found by using the expression:
[tex]\begin{gathered} SE_p=\sqrt[]{\frac{p(1-p)}{n}} \\ SE_p=\sqrt[]{\frac{0.5\cdot(1-0.5)}{90}} \\ SE_p=\sqrt[]{\frac{0.5\cdot0.5}{90}} \\ SE_p=\sqrt[]{\frac{0.25}{90}} \\ SE_p=\sqrt[]{0.0027777777777778} \\ SE_p=0.053 \end{gathered}[/tex]The answer is D.
