What Is the Correct Formula for Calculating the Standard Deviation $\sqrt { \frac { \sum ( X - M ) } { ( N - 1 ) } }$

Multiple Choice

What is the correct formula for calculating the standard deviation of a sample when one is NOT trying to estimate the population standard deviation?

A) $\sqrt { \frac { \sum ( X - M ) } { ( N - 1 ) } }$
B) $\sqrt { \frac { \sum ( X - M ) ^ { 2 } } { ( N - 1 ) } }$
C) $\sqrt { \frac { \sum ( X - M ) ^ { 2 } } { N } }$
D) $\frac { \sqrt { \sum ( X - M ) ^ { 2 } } } { N - 1 }$