Recall the Application About the Incentives to Buy Hybrid Vehicles

Recall the Application about the incentives to buy hybrid vehicles to answer the following question(s) .
-According to the Application,which of the following increased the incentive to buy hybrid vehicles?

A) Purchases of hybrid vehicles qualified for a $3,400 subsidy from the federal government.
B) Oil prices decreased.
C) Hybrid vehicles were more expensive than regular vehicles.
D) Hybrid vehicles had similar emissions as the non-hybrid vehicles.