Answer:C is most likely a metalloid
Explanation:A is a metal while B is a non metal. This is because when we look at the properties of metals, they are very lustrous and have a high conductivity. On the other hand, non metals are the opposite but metalloids have properties the are inbetween ie, they react with either an acid or base, and have a medium electrical conductivity unlike metals(high) anc non metals(low).
Answer:
Protein
Explanation:
Protein is used to make insulation (like fat) and is used to store energy taken form food (please tell me if this works)