text: <unk> s are rigid organs that form part of the endoskeleton of vertebrates. They function to move, support, and protect the various organs of the body, produce red and white blood cells and store minerals.  Because<unk> s come in a variety of shapes and have a complex internal and external structure,  they are lightweight, yet strong and hard, in addition to fulfilling their many other functions.  One of the types of tissues that makes up<unk>  is the mineralized osseous tissue, also called<unk>  tissue, that gives it rigidity and honeycomb-like three-dimensional internal structure. Other types of tissue found in<unk> s include marrow, endosteum and  periosteum, nerves, blood vessels and cartilage.  There are 206<unk> s in the adult body, and about 300<unk> s in a infants body.
option_0: Bone
option_1: Tissue 
option_2: Cartilage
option_3: Heart
option_4: Nervous tissue
option_5: Brain
option_6: Hair
option_7: Skeletal muscle