Ans: Option (B) Mitosis
DNA replication occurs just before the process of cell division, which is also called mitosis.
Mitosis is when the cell is being divided into two, and this is when DNA starts to replicate and it produces more and more cells and the process continues. In other words, mitosis is a part of the cell cycle when replicated chromosomes are separated into two new nuclei. Before that process(mitosis), DNA replication occurs. Hence the correct option is (B) Mitosis.