A sample of $5$ measurements, randomly selected from a normally distributed population, resulted in a sample mean, $\overline{x} = 7.9$ and sample standard deviation $s = 1.18$. Using $\alpha = 0.05$, test the null hypothesis that the mean of the population is $9.8$ against the alternative hypothesis that the mean of the population, $\mu < 9.8$ by giving the following:
(a) $\ $ the degree of freedom $\ $
(b) $\ $ the critical $t$ value $\ $
(c) $\ $ the test statistic $\ $

The final conclustion is

A. There is not sufficient evidence to reject the null hypothesis that $\mu = 9.8$.
B. We can reject the null hypothesis that $\mu = 9.8$ and accept that $\mu < 9.8$.