Where are apocrine glands mainly derived from?

Apocrine glands are a type of sweat gland that primarily differentiate from the dermis and subcutaneous fat layer of the skin. These glands are found mainly in areas such as the underarms and groin and are responsible for producing a thicker, milky sweat that can be associated with body odor when metabolized by bacteria on the skin's surface. The presence of these glands deeper in the skin layers means they rely on the surrounding tissue for structure and function. This anatomical context helps clarify why the correct answer highlights the importance of the dermis and subcutaneous fat as their primary source.

Each of the other choices pertains to locations or tissue types where apocrine glands are not formed. Skin surface does not encompass the deeper layers where these glands originate. Muscle tissue and bone marrow are also unrelated to the structure or function of apocrine glands, further emphasizing the accuracy of the selected answer.