Final answer:
The true statement concerning secondary ovarian follicles is that they contain a secondary oocyte. Secondary follicles have multiple layers of granulosa cells, require FSH for growth, possess a theca externa, and have an antrum with follicular fluid, which are all characteristics not described in the other options provided.
Step-by-step explanation:
The correct answer to the question "Which of the following statements concerning secondary ovarian follicles is true?" is (B) They contain a secondary oocyte. Secondary follicles develop from primary follicles and contain a primary oocyte that matures into a secondary oocyte upon the onset of ovulation. These follicles are characterized by multiple layers of granulosa cells and produce estrogens aided by the surrounding theca cells. The primary oocyte is surrounded by a protective layer called the zona pellucida and is bathed in follicular fluid that collects in the antrum of the tertiary follicle.
Secondary ovarian follicles indeed have multiple layers of granulosa cells, and their maturation is stimulated by follicle-stimulating hormone (FSH). They also have a well-developed antrum filled with liquor folliculi, and the theca externa, a layer of connective tissue, is present around these follicles.
Therefore, options A, C, D, and E are not true for secondary follicles. The statement that secondary follicles lack liquor folliculi (A) is incorrect, as the antrum containing the follicular fluid begins to form at this stage. While FSH is required for growth of the follicle (C), it is not true that their continued maturation requires only FSH; luteinizing hormone (LH) also plays a role. They do possess a theca externa (D), and they have multiple layers of granulosa cells (E), not just a single layer.