The best answer would be:
A. The stage during which the cell carries out normal cellular functions and makes copies of its DNA.
If you'd like to know more about it, read on:
The cell actually spends most of its life in this phase of the cycle. This is the point where the cell grows and makes copies of its DNA in preparation for cell division.
Interphase is divided into 3 steps:
G1 phase - the cell grows larger and it makes copies of its organelles. (also known as the first gap phase)
S phase - the cell synthesizes copies of its DNA that is found in the nucleus.
G2 phase - it grows more and makes proteins in preparation for cell division. The cell even reorganizes its organelles in this phase.
