A sample of 35 individuals is selected from a population with u = 80 and a treatment is administered to the sample. If the treatment has no effect, then 0 a) the sample mean should be very different from 80 and should lead you to reject the null hypothesis 0 b) the sample mean should be very different from 80 and should lead you to fail to reject the null hypothesis 0 c) the sample mean should be close to 80 and should lead you to reject the null hypothesis (9 d) the sample mean should be close to 80 and should lead you to fail to reject the null hypothesis