## Core Concept
The M phase of mitosis, also known as the mitotic phase, is a critical stage of the cell cycle where the replicated DNA and cellular components are divided into two daughter cells. This phase is characterized by several key events, including prophase, metaphase, anaphase, and telophase, followed by cytokinesis. The M phase ensures genetic material is equally distributed to daughter cells.

## Why the Correct Answer is Right
The M phase involves the condensation of chromosomes, dissolution of the nuclear envelope, alignment of chromosomes at the metaphase plate, separation of sister chromatids, and reformation of the nuclear envelope around each set of chromosomes. DNA replication, however, occurs during the S phase of the cell cycle, not during the M phase.

## Why Each Wrong Option is Incorrect
- **Option A:** Chromosome condensation occurs during prophase of the M phase.
- **Option B:** Nuclear envelope breakdown happens during prophase of the M phase.
- **Option C:** Sister chromatid separation occurs during anaphase of the M phase.
- **Option D:** These are the events that actually do occur in M phase as described.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the cell cycle consists of G1 (gap 1), S (synthesis), G2 (gap 2), and M (mitosis) phases. DNA replication specifically occurs during the S phase. Disruptions in the cell cycle, including the M phase, can lead to uncontrolled cell growth and cancer.

## Correct Answer: D.