A Reaction Is Carried Out Under an Atmosphere of Oxygen $22^\degree$

Multiple Choice

A reaction is carried out under an atmosphere of oxygen. As the reaction proceeds, oxygen is consumed. The reaction started in a 500 ml flask, under a pressure of 1015 mm Hg, and a temperature of $22^\degree$ C. How many moles of oxygen had been consumed if at the end of the reaction the pressure was 790 mm Hg and the temperature did not change?

A) 0.0286 moles
B) 46.6 moles
C) 0.0223 moles
D) 0.0250 moles
E) 0.00610 moles