When You Research Question About the Difference Between Three or More

When you research question about the difference between three or more population means, the null hypothesis states that all the means are equal. Should the alternative hypothesis always state that at least two population means are not equal or it can vary? Explain why, or why not.

A) The alternative hypothesis can only state that at least two population means are not equal, because we are not interested in cases when one population mean is greater than other population means.
B) The alternative hypothesis can only state that all population means are not equal, because we cannot rank the population means from the smallest to the largest before the study.
C) The alternative hypothesis can only state that all population means are not equal, because we need the null and the alternative hypotheses to present all sample space.
D) Any statement suitable for the particular research can be stated as an alternative hypothesis.