Use the following data to answer Questions 65 through 68.
　　Two samples were drawn from two normally distributed populations. For the first sample, the mean was $50 and the standard deviation was $5. For the second sample, the mean was $55 and the standard deviation was $6. The first sample consists of 25 observations and the second sample consists of 36 observations. (Note:In the questions below, the subscripts "1" and "2" indicate the first and second sample, respectively.)Using a 5% level of significance for a test of the null of H0:= versus the alternative of Ha:≠, the null hypothesis:

A.cannot be rejected.

B.should be rejected.

C.cannot be tested using the sample information provided.