Seminiferous tubules develop central lumen after

The correct option is Puberty.

Step-by-step Explanation:
1. Embryonic and Prepubeal Development: During embryonic development and throughout childhood (prepuberal time), the structures that will become the seminiferous tubules exist as solid structures called testis cords or sex cords. These cords lack a hollow cavity or central channel (lumen) and are composed primarily of primordial germ cells and immature Sertoli cells.
2. Hormonal Activation: At the onset of puberty, the hypothalamus increases secretion of gonadotropin-releasing hormone (GnRH), which stimulates the pituitary gland to release luteinizing hormone (LH) and follicle-stimulating hormone (FSH). This hormonal surge triggers the production of testosterone by Leydig cells.
3. Canalization: The increased levels of FSH and testosterone stimulate the maturation of Sertoli cells and the initiation of spermatogenesis. Sertoli cells begin to secrete fluid, and the solid testis cords undergo a hollowing-out process called canalization, which creates the central lumen. Consequently, the solid cords are transformed into functional, hollow seminiferous tubules that can transport spermatozoa.