Hydrogen and oxygen react to produce water according to the following equation.

2H2 + O2 → 2H2O

The molar mass of hydrogen gas (H2) is 2 g/mol. The molar mass of oxygen gas (O2) is 32 g/mol. When the reaction starts with 64 grams of oxygen and a sufficient quantity of hydrogen, how many moles of water are produced?

A 8
B 2 ***
C 18
D 4