A Researcher Reports That "The Average Shopper in the Sample $\mu$

A researcher reports that "the average shopper in the sample (n = 12) purchased $65.00 worth of items ( $\mu$ = $65.00) during a busy shopping day." What mistake was made is this citation?

A) None;this citation is written appropriately.
B) The sample mean is written using the wrong notation.
C) The sample size is written using the wrong notation.
D) both B and C