Which gland produces testosterone in males?

A Thyroid
B. Pituitary
C. Testis
D. Adrenal

The gland that produces testosterone in males is the C. Testis.

C. Testis

The gland that produces testosterone in males is the testis. To arrive at this answer, you can use your knowledge of human anatomy and endocrine system or perform a simple search using credible sources.

The first step is to understand the function of testosterone and its relation to the reproductive system. Testosterone is a hormone that plays a crucial role in male sexual development and function, including the production of sperm, the growth of facial and body hair, and the deepening of the voice. Knowing this, we can narrow down our options to the glands involved in the male reproductive system.

Now, let's evaluate the given options:
A. Thyroid: The thyroid gland is responsible for producing hormones that control metabolism, growth, and development, but not testosterone.
B. Pituitary: The pituitary gland is often referred to as the "master gland" because it controls numerous other glands in the body. While it does play a role in the production of certain hormones related to reproduction, it is not the primary gland responsible for producing testosterone.
C. Testis: The testes, also known as testicles, are the male reproductive organs responsible for producing sperm and testosterone. This is the correct answer.
D. Adrenal: The adrenal glands are situated on top of the kidneys and produce various hormones, including cortisol and adrenaline. However, they are not the primary gland responsible for testosterone production in males.

Therefore, the correct answer is C. Testis.