What is the name of the compound (NH4)3PO3? Why is special about this compound? Choose one answer. a. Ammonium phosphate; this covalent compound is made up of two polyatomic ions, ammonium and phosphate. b. Ammonium phosphite; this ionic compound is made up of two polyatomic ions, ammonium and phosphite. c. Ammonium phosphate; this ionic compound is made up of two polyatomic ions, ammonium and phosphate. d. Ammonium phosphite; this covalent compound is made up of two polyatomic ions, ammonium and phosphite.