[单选题]
A container of an ideal gas at 1 atm is compressed to one ,f s4l;jf7lj52pm8jewik0py-third its 7 du91ns4, 0+hgcq2jo w shpgzvolume, with the temperature held constant. s4,d uoc+97q1wngsh 2 z0pj hgWhat is its final pressure?
A. $1/3 \; atm$
B. $1 \; atm$
C. $3 \; atm$
D. $9 \; atm$
