The correct answer is: B. Centrioles
Centrioles are small, cylindrical organelles found in the centrosome of animal cells. They are involved in the formation of the spindle apparatus, which is necessary for cell division.
The centromere is a region of a chromosome that contains the kinetochore, which is the attachment site for the spindle microtubules. The centromere is not involved in the initiation of cell division.
The centrosome is a structure located near the nucleus of animal cells. It contains two centrioles, which are involved in the formation of the spindle apparatus. The centrosome is not involved in the initiation of cell division.
Ribosomes are small organelles that are found in the cytoplasm of all cells. They are responsible for protein synthesis. Ribosomes are not involved in the initiation of cell division.