A 9.0-V battery costs $1.49 and will run a portable CD player for 6.0 hours before running down and needing to be replaced. If this battery supplies a current of 25 mA to the player, what is the cost of the energy provided by the battery in dollars per kWh?

a). $11/kWh 

b). $11,000/kWh 

c). $110/kWh 

d). $1100/kWh