Which of the Formulas Below Would Be Used to Determine $$n = \frac { \sigma ^ { 2 } z ^ { 2 } } { D ^ { 2 } }$$

Multiple Choice

Which of the formulas below would be used to determine the sample size using the formula for the standard error of the mean?

A) $$n = \frac { \sigma ^ { 2 } z ^ { 2 } } { D ^ { 2 } }$$
B) $$n = \frac { \pi ( 1 - \pi ) z ^ { 2 } } { D ^ { 2 } }$$
C) $$\sigma X = D / z$$
D) A and C are correct.