[单选题]
A heat engine absorbs 6q:f7 ;duq9 fdm4 kcal of h n53lwsx.6xu))zhxgp3p kx)k / n: zoleat each cycle and exhausts 42 kcal. Calculate the nnp)z3o hg/3: xp 6kxuwx5sk.lzl)x )work done each cycle.
A. $22 \; kcal$
B. $42 \; kcal$
C. $64 \; kcal$
D. $106 \; kcal$
