Overactive sebaceous glands can cause:a) fine hairs on the forehead to become brittle. b) the forehead's skin to become dry. c) bacteria on the forehead's skin to grow and multiply freely. d) seborrhea, a disease characterized by red, itchy lesions on the scalp.

d) seborrhea, a disease characterized by red, itchy lesions on the scalp.

Explanation:

Sebaceous gland are the glands which are usually present beneath the skin and with the hair follicles. They are also known as oil-producing glands as they released sebum.  

If the sebaceous gland becomes too active and secrete extra sebum than it can cause a condition called Seborrhoea. In Seborrhoea microbe  like Malassezia fungi species colonizes the area where sebum is produced and initiates local inflammatory response which causes scaly patches,  itchy lesions, and red skin. So the correct answer is d.