Answer:
D. sister chromatids; centromere
Explanation:
Chromosomes are made up of two filaments joined by the centromere. Each of these filaments is called a chromatid. The two chromatids found on a duplicated chromosome (duplication occurs during the interphase in cell division) are called sister chromatids. In the process of cell division, they separate, each going to a daughter cell.
In other words, we can say that after DNA replication during the S phase of the interphase, each chromosome has a copy and the cell is now 4n. We call these identical pairs of sister chromatids and they are held together by a centromere.
