The Following Information Was Obtained from Matched Samples Taken from Two

Multiple Choice

The following information was obtained from matched samples taken from two populations. The daily production rates for a sample of workers before and after a training program are shown below. Assume the population of differences is normally distributed. ​
Given that the null hypothesis to be tested is H₀: μd = 0,

A) the null hypothesis should be rejected.
B) the null hypothesis should not be rejected.
C) the alternative hypothesis should be revised.
D) the null hypothesis should be revised.