Upgrade subject to access all content

Which combination would produce the smallest standard deviation for the sampling distribution of a sample proportion?

$n = 50$ and $p =0 .40$

$n = 50$ and $p = 0.70$

$n = 200$ and $p =0.10$

$n = 200$ and $p =0.40$

$n = 200$ and $p =0.70$