TABLE 10-4 Two Samples Each of Size 25 Are Taken from Independent

TABLE 10-4
Two samples each of size 25 are taken from independent populations assumed to be normally distributed with equal variances.The first sample has a mean of 35.5 and standard deviation of 3.0 while the second sample has a mean of 33.0 and standard deviation of 4.0.
-In testing for differences between the means of two related populations,the null hypothesis is

A) H₀ : μ_D = 2.
B) H₀ : μ_D = 0.
C) H₀ : μ_D < 0.
D) H₀ : μ_D > 0.