Question

sebaceous gland produces

sweat mainly in the groin and armpit
sweat mainly in the forehead
oily secretion
waste products

Explanation:

Sebaceous glands are located in the skin. Their main function is to secrete sebum, which is an oily substance. Sweat is mainly produced by sweat glands. The groin and armpit are areas where apocrine sweat glands are more prominent (producing a different type of secretion than sebaceous glands). The forehead also has sweat glands. Waste products are a more general term not specific to sebaceous gland secretion. Sebaceous glands specifically produce an oily secretion (sebum) which helps lubricate the skin and hair.

Answer:

oily secretion