Leydig cells present in the testis which are also called as interstitial cells of Leydig. These cells are present adjacent to seminiferous tubules. The main function of Leydig cells is to produce testosterone in the presence of the luteinizing hormone. So, the correct answer is option 'B'.

Production of Testosterone in Adult Males

Testosterone is a male sex hormone that is responsible for the development of male physical characteristics and reproductive function. It is produced in the testes of adult males. The production of testosterone is regulated by the hypothalamus-pituitary-gonadal (HPG) axis.

Interstitial Cells of Leydig

The interstitial cells of Leydig are located in the connective tissue surrounding the seminiferous tubules in the testes. These cells are responsible for the production of testosterone in adult males. They are stimulated by the luteinizing hormone (LH) released by the anterior pituitary gland. LH binds to receptors on the interstitial cells of Leydig and stimulates the production of testosterone.

Seminiferous Tubules

The seminiferous tubules are responsible for the production of sperm in adult males. They are lined with Sustenacular (Sertoli) cells that support the development of sperm cells. However, these cells do not produce testosterone.

Bulbourethral Glands

The bulbourethral glands, also known as Cowper's glands, are responsible for the production of pre-ejaculate fluid in adult males. This fluid helps to lubricate the urethra and neutralize any residual urine that may be present. However, these glands do not produce testosterone.

Conclusion

In conclusion, testosterone in adult males is primarily produced by the interstitial cells of Leydig located in the testes. The production of testosterone is regulated by the hypothalamus-pituitary-gonadal (HPG) axis. The seminiferous tubules and bulbourethral glands do not produce testosterone.