[单选题]
A gas is expanded to twice t:3z*z3 h9-xms6jhhdy d5 *pujmyk*nits original volume with no change in its temperatupf/ce* rp6581d p7 sru cr3h:o qm+ermre. Th pmercf+d:rp 7m3r rc/o8ups 6*1e5qhis process is
A. isothermal
B. isochoric
C. isobaric
D. adiabatic
