The first part of interphase is called

Explanation:
Let's break down what interphase is and its different parts.

Interphase is like the preparation stage for a cell before it divides.
It's a long period of growth and activity where the cell gets ready for cell division.

Interphase has three main phases:
G1 phase: This is the first gap phase. The cell grows in size and produces proteins and organelles.
S phase: This is the synthetic phase. The cell duplicates its DNA (DNA replication).
G2 phase: This is the second gap phase. The cell continues to grow and makes more proteins and organelles needed for cell division.

M phase: This is the mitotic phase or cell division phase. (Not part of interphase)

So, the first part of interphase is the G1 phase.
Correct Answer: B