Final answer:
The basal layer of the uterine endometrium, the stratum basalis, does not shed during menstruation; it is supplied by coiled arteries and contains glands, contrary to options (B), (A), and (D) in the question.
Step-by-step explanation:
The basal layer of the uterine endometrium, known as the stratum basalis, is the layer that remains constant and does not get shed during menstruation. This layer is adjacent to the myometrium and is part of the lamina propria. It is not the stratum basalis but rather the stratum functionalis that grows and thickens during the menstrual cycle in response to hormones and then sheds during menstruation if fertilization does not occur.
The stratum basalis has glands, and it is the stratum functionalis that is supplied by coiled arteries known as spiral arteries. These arteries supply the functional layer during the luteal phase of the menstrual cycle to maintain the tissue if an embryo implants. Therefore, the correct answer is that the basal layer of the uterine endometrium becomes sloughed during menstruation (B) is incorrect, (A) has no glands is incorrect as it indeed has glands, (D) is supplied by straight arteries is incorrect, and thus (C) is supplied by coiled arteries is the correct answer.