Sister chromatids are

A. The two new cells created when cells divide

B. Joined strands of duplicated DNA

C. A term used to describe two people with identical DNA (not necessarily sisters)

you didn't give any options but heres what i can tell you: an inference is likely to change based on additional observations. the latter is something that you have seen or sensed using your sensory organs while the former is like a conclusion out from what you have observed.