which of the following are the functions of the integumentary system?
blood cell production in soft marrow tissues and mineral reserves
largest organ of the body for protection and body temperature regulation
vitamin d production and pumping blood through vessels
voluntary movement and contractile movement

Blood cell production in soft marrow tissues and mineral reserves occurs in the bones. This means that this is the skeletal system.

Largest organ of the body for protection and body temperature regulation is done by they skin. Skin protects internal organs from bactiria or pathogens from getting inside the body. The skin also sweats to keep the body at a constent temperatrue. Skin is part of the integumentary system

Vitamin D production and pumping blood through vessels occurs in the heart/veins which are part of the cardiovascular system.

Voluntary movement and contractile movement is done by our muscles, making this par of the muscular system.

The only possible answer is:  Largest organ of the body for protection and body temperature regulation

Hope this helped!

~Just a girl in love with Shawn Mendes