Final answer:
A cut that reaches the sebaceous glands and hair follicles has penetrated both the epidermis and dermis layers of the skin.
Step-by-step explanation:
When a cut reaches the sebaceous glands and hair follicles, it has penetrated into the dermis layer of the skin. The correct answer to which layers of the skin have been reached is b. epidermis and dermis. The epidermis is the outermost layer of skin, and the sebaceous glands and hair follicles, being embedded in the dermis beneath the epidermis, indicate the cut has gone through both these layers.
If only the epidermis were cut, there would not be any bleeding, as it doesn't have blood vessels. The fact that sebaceous glands and hair follicles are affected further confirms that the cut has reached a deeper layer where these structures reside.