Consider Two Equal-Volume Flasks of Gas at the Same Temperature $\frac { 32 } { 38 }$

Consider two equal-volume flasks of gas at the same temperature and pressure.One gas,oxygen,has a molecular mass of 32.The other gas,nitrogen,has a molecular mass of 28.What is the ratio of the number of oxygen molecules to the number of nitrogen molecules in these flasks?

A) $\frac { 32 } { 38 }$
B) $\frac { 28 } { 32 }$
C) $\sqrt { \frac { 28 } { 32 } }$
D) $\sqrt { \frac { 32 } { 28 } }$
E) $\frac { 1 } { 1 }$