Orlando bought a new couch for $2,904, using the furniture store's finance plan. He will pay $121 a month for 24 months. Which equation can Orlando use to find out how much money he still owes after each month of the plan?

Select one:
a. y=2,904+121x
b. y=2904−121x
c. y=121x−2,904
d. y=121x