Chromosomes Are Often Represented as an X, with Two Sister

Chromosomes are often represented as an X, with two sister chromatids attached at the centromere.Do chromosomes always look like an X?

A) Yes, chromosomes are always made up of two sister chromatids attached.
B) No, chromosomes only look like an X when condensed, but they always have two sister chromatids attached.
C) No, chromosomes only look like an X following DNA replication, and before cell division; the rest of the time, they only have one sister chromatid each.
D) No, chromosomes only look like an X right after cell division; the rest of the time, they have only one sister chromatid each.