Energy usage is measured in kilowatt-hours, KWh . After 7 a.m., energy usage on a university campus increases at a rate of 21% per hour. Prior to 7 a.m., 15,040kWh have been used. The university's daily goal is to keep its enérgy usage less than or equal to 100,000kWh . Which inequality can be used to determine the number of hours, t , after 7a .m. when the energy usage on campus will be less than or equal to 100,000?

A. 15,040(1.21)ᵗ <= 100,000
B. 15,040(1.79)ᵗ <= 100,000
C. 15,040(0.79)ᵗ <= 100,000
D. 15,040(1.021)ᵗ <= 100,000