Which of the following is characterised by the presence of a fluid-filled cavity and a theca layer organised into theca interna and theca externa?

The theca layer is organised into an inner theca interna and an outer theca externa in the tertiary follicle. 

• The theca interna is the innermost layer of the theca. It is a cellular layer that contains steroidogenic cells capable of producing androgens, such as testosterone. These androgens are essential precursors for the production of estrogens by the granulosa cells within the follicle.
• The theca externa is the outer layer of the theca. It is a more fibrous and connective tissue layer that provides structural support to the follicle and separates it from the surrounding ovarian tissue.