The oily substance that lubricates the mammalian hair to keep it flexible and water repellent is secreted by the
sweat glands
sebaceous glands
fatty cells
granular layer
Correct answer is B
The normal function of sebaceous glands is to produce and secrete sebum, a group of complex oils including triglycerides and fatty acid breakdown products, wax esters, squalene, cholesterol esters and cholesterol. Sebum lubricates the skin to protect against friction and makes it more impervious to moisture.