The allowable leak limit for household refrigerators differs from the allowable leak limit for commercial refrigerators and freezers because of $\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_.$

A$)$ the higher technical sophistication of the commercial technician

B$)$ the difference in the room sizes assumed in commercial and residential applications

C$)$ the greater likelihood of children in residential applications

D$)$ the greater likelihood of pregnant women in residential applications