Which of the Following Statements Are True When $\bar { X }$

Multiple Choice

Which of the following statements are true when $\bar { X }$ is the mean of a random sample of size n from a normal distribution with mean $\mu$ ?

A) The random variable $Z = ( \bar { X } - \mu ) / ( S / \sqrt { n ) }$
Has approximately a standard normal distribution for large n.
B) The random variable $T = ( \bar { X } - \mu ) / ( S / \sqrt { n ) }$
Has a t-distribution with n-1 degrees of freedom for small n.
C) The normal distribution is governed by two parameters, the mean $\mu$
And the standard deviation $\sigma$
)
D) A t-distribution is governed by only one parameter, called the number of degrees of freedom.
E) All of the above answers are true.