Answer:
Meiosis.
Explanation:
Meiosis may be defined as the process of cell division in which a parent cell divides in to four daughter cells. Meiosis is also known as reduction division as the chromosome number is reduced to half in the daughter cells.
The spermatocytes can move from the outer wall and increase in size. They undergo the process of meiosis to produce the secondary spermatocytes the resulting sperms has the 23 number of chromosomes.
Thus, the answer is meiosis.