Which of the following will likely lead to cost-push inflation?

a. Consumers become more comfortable with debt, increasing their spending as they take more loans.
b. An ongoing war causes government spending to nearly double in quantity.
c. Exports increasing dramatically after a relative drop in price.
d. An increasing in the price of oil has reduced supply of all goods and services that use oil as an input.

d. An increase in the price of oil has reduced supply of all goods and services that use oil as an input.