Middle layer of skin is?

The middle layer of the skin is the dermis.

The human skin is the largest organ of body and consists of three layers: epidermis, dermis and hypodermis. Epidermis is the outermost layer of the skin, hypodermis is the innermost layer, and dermis is the middle layer which is thickest comparatively. It contains hair follicles, sweat glands (sweat producing gland), blood vessels, lymph vessels, and sebaceous gland (sebum producing gland). 

Therefore the Middle layer of skin is the dermis.

Hence the correct answer is option C.