Final answer:
A human sperm cell contains 23 chromosomes, which are haploid and result from the process of meiosis during spermatogenesis.
Step-by-step explanation:
A human sperm cell contains 23 chromosomes, which is the correct answer to the student's question. The human body cells, also known as somatic cells, have a total of 46 chromosomes, arranged in pairs, and are known as diploid (2n). However, human gametes, which include sperm and egg cells, contain only half the number of chromosomes, or 23 chromosomes, making them haploid (1n).
During the process known as spermatogenesis, diploid cells (which have 46 chromosomes) undergo division through meiosis to produce sperm cells. As a result, each sperm cell ends up with 23 unpaired chromosomes. This is to ensure that when a sperm cell and an egg cell combine, the resulting zygote will have the correct number of chromosomes: 46 or 23 pairs. Hence, the correct option from the given choices is 'a. 23 chromosomes.'