arf! magazine reports that on average normal dogs sleep a minimum of 12 hours per day. A sample of 25 Cockadoodles slept only 11.5 hours per day with s= 4. At a 95% level of confidence, test the hypothesis that the cockadoodles are normal.

a. no because the test statistic is negative

b. no because the critical value is negative

c. yes because Ho is accepted

d. no because Ho is rejected