Nurse cells are responsible for:
a. aiding spermatogenesis
b. forming a blood-testis barrier to protect developing sperm
c. maintaining high levels of testosterone in the seminiferous tubules
d. secreting inhibin
e. all of the above

The correct answer is e. all of the above.

Explanation:

Nurse cells are also called sertoli cells and are located in the seminiferous tubules in the testes. They provide nourishment to the growing sperms by providing nutrients from surrounding cells.

During the development of of sperms they become genetically different from other cells so nurse cells form blood testes barrier to protect them from immune cells.

Nurse cells concentrate the testosterone in seminiferous tubules which is necessary for proper development of sperms. They also secrete inhibin which stop FSH secretion from anterior pituitary therefore regulate the spermatogenesis.