Which of the Following Statements Are True If $X _ { 1 } , X _ { 2 } , \cdots \cdots , X _ { n }$

Which of the following statements are true if $X _ { 1 } , X _ { 2 } , \cdots \cdots , X _ { n }$ is a random sample from a distribution with mean $\mu$ ?

A) The sample mean $\bar { X }$
Is always an unbiased estimator of $\mu$
)
B) The sample mean $\tilde { \mu }$
Is an unbiased estimator of $\mu$
If the distribution is continuous and symmetric.
C) Any trimmed mean is an unbiased estimator of $\mu$
If the distribution is continuous and symmetric.
D) None of the above statements are true.
E) All of the above statements are true.