Final answer:
Answer A. Sex; autosomes is correct. Humans have one pair of sex chromosomes and 22 pairs of autosomes. Sex chromosomes are either XX or XY, and autosomes contain genes unrelated to sex.
Step-by-step explanation:
Humans normally have one pair of sex chromosomes (either XX or XY), and 22 pairs of chromosomes called autosomes that are found in both males and females. The correct answer to the student's question is A. Sex; autosomes.
The autosomes are chromosomes that contain genes for characteristics that are unrelated to sex, while sex chromosomes are involved in determining the biological sex of an individual.
In human karyotypes, the 23rd pair of chromosomes are the sex chromosomes, which can be two X chromosomes (XX) in females or one X and one Y chromosome (XY) in males. The remaining 22 pairs are autosomes, essential for various bodily functions and characteristics.