[单选题]
In an isochoric process, the inter2 ,s8 wfyp:.dbehq 4m)bg.m*td glu2sc n(if 2nal energy of a system decre-.kk2*opy h1*l l4 ru sczvu rn+ohg+8ases by 50 J. What is the work u+r-+.z8s kk1grc*loly h 4vn2up *h odone?
A. zero
B. $50 \; J$
C. $-50 \; J$
D. none of the above
