A Sample of 40 Students Enroll in a Program That $\bar { x } = 17$

A sample of 40 students enroll in a program that claims to improve scores on the quantitative reasoning portion of the Graduate Record Examination (GRE) . The participants take a mock GRE test before the program begins and again at the end to measure their improvement.
The mean number of points improved was $\bar { x } = 17$ . Assume the standard deviation is $\sigma = 65$ and let $\mu$ be the population mean number of points improved. To determine whether the program is effective, a test is made of the hypotheses $H _ { 0 } : \mu = 0$ versus $H _ { 1 } : \mu > 0 .$
Compute the $P$ -value.

A) $1.6541$
B) $0.0246$
C) $0.0123$
D) $0.0491$