Final answer:
The cellular reproduction process forming two identical nuclei is called mitosis, which includes phases ensuring the distribution of identical genetic material into daughter cells.
Step-by-step explanation:
The process of cellular reproduction that occurs in the nucleus forming two identical nuclei is known as mitosis. During mitosis, the cell undergoes a series of stages — prophase, prometaphase, metaphase, anaphase, and telophase — culminating in the division of the cell nucleus. This results in two genetically identical daughter cells, each with the same number of chromosome sets as the original cell, maintaining the diploid state in most plants and animals. Therefore, the correct answer to the question is B. Mitosis.