[单选题]
An ideal gas has a pressvqa1:p4r/t *gw:npx w u)2q4.+vnwus oydz 8qire of 2.5 atm, a volume of 1.0 L at a temperature of $30 \; ^{\circ}C$. How many molecules are there in the gas?
A. $6.1 \times 10^{23}$
B. $6.0 \times 10^{22}$
C. $2.4 \times 10^{22}$
D. $2.3 \times 10^{23}$
