The Distribution of Certain Test Scores Is a Nonstandard Normal $z$

The distribution of certain test scores is a nonstandard normal distribution with a mean of 50 and a standard deviation of 6 . What are the values of the mean and standard deviation after all test scores have been standardized by converting them to $z$ -scores using $z = ( x - \mu ) / \sigma$ ?

A) The mean is 100 and the standard deviation is 10 .
B) The mean is 0 and the standard deviation is 1 .
C) The mean is 10 and the standard deviation is 100 .
D) The mean is 1 and the standard deviation is 0 .