B. Are produced only by living things
Answer: The correct option is 
Explanation:
Atomic mass of calcium ,Ca = 40.07 g/mol
Atomic mass of chlorine ,Cl = 35.5 g/mol
Molar mass of
:
= (Atomic mass of Ca+2 × (Atomic mass of Cl))
= (40.07 g/mol + (2 × 35.5))=111.07 g/mol

Hence, the correct option is 
My guess is the last 2... <span>phosphorus and potassium</span>