[单选题]
A heat engine absorbs 64 kcal of heat each cycle and exhausts 42 kcal. tv7p 3qg8)vk v6hl 9w;7.8 mu+esqh c6vximw a Calcula0a 9yt8i 8 bjidmz/i9kte the work d0j b9im y/8zt9aii 8kdone each cycle.
A. $22 \; kcal$
B. $42 \; kcal$
C. $64 \; kcal$
D. $106 \; kcal$
