What Would Be the Cause of Total Spending Rising from One

What would be the cause of total spending rising from one year to the next?

A) The economy must be producing a larger output of goods and services.
B) Prices at which goods and services are sold must be higher.
C) Either the economy must be producing a larger output of goods and services, or the prices at which goods and services are sold must be higher, or both.
D) Employment or productivity must be rising.