In anaphase, the number of cells is generally not specific to the phase itself; rather, anaphase is a stage of mitosis where the chromosomes are being separated into two daughter cells. The number of cells in anaphase would depend on how many cells are undergoing mitosis at that time.
Given your options, if you are looking for a context-based answer, the selection would depend on the specific scenario or organism being referenced. However, typically in a standard human cell culture, you would observe a fraction of cells in anaphase at any given time.
If this question is part of a specific biological context (like a counting experiment), please provide more details, and I'd be happy to help clarify further!