Sample Size $= 256$ , Sample Mean $= 40$ , Sample Standard Deviation

Multiple Choice

Sample size $= 256$ , sample mean $= 40$ , sample standard deviation $= 13$
What is the $95 \%$ confidence interval for the population mean?

A) $39.2 < \mu < 40.8$
B) $38.4 < \mu < 41.6$
C) $39.9 < \mu < 40.1$
D) $8 < \mu < 18$