Students in a science class observed that when a strip of magnesium (Mg) metal was placed in a test tube containing hydrochloric acid (HCl), the magnesium began to bubble as hydrogen gas and magnesium chloride are formed. Which of the following choices show both the correctly balanced equation and identify the type of reaction? A.
Mg + 2HCl →2H2 + MgCl2 (single replacement)

B.
Mg + 2HCl →H2 + MgCl2 (single replacement)

C.
Mg + 2HCl →H2 + MgCl2 (synthesis)

D.
2Mg + HCl →H2 + 2MgCl2 (synthesis)