2-126 Consider a refrigerator that consumes 320 W of electric power when it is running. If the refrigerator runs only one quarter of the time and the unit cost of

electricity is $0.13/kWh, the electricity cost of this refrigerator per month (30 days) is (a) $4.9 (b) $5.8 (c) $7.5 (d) $8.3 (e) $9.7