Final answer:
The alternate hypothesis that indicates the mean of x2 population is smaller than that of x1 population is C. H1: μ1 > μ2 or H1: μ1 - μ2 > 0, which is used in a right-tailed test. Option C is correct.
Step-by-step explanation:
When conducting a test for the difference of means for two independent populations x1 and x2, where we are considering whether the mean of the x2 population is smaller than that of the x1 population, the appropriate alternate hypothesis would be H1: μ1 > μ2.
This hypothesis can also be expressed as H1: μ1 - μ2 > 0, indicating that the first population has a greater mean than the second one. Both these forms of the hypothesis are used in a right-tailed test, where we anticipate the value of the first mean to be larger than the second. The answer to the student's question is therefore C. H1: μ1 > μ2 or H1: μ1 - μ2 > 0.