When looking at how the economy changes over time, what does the term inflation specifically describe about...

When looking at how the economy changes over time, what does the term inflation specifically describe about the overall cost of goods and services that people buy?
A sudden increase in government taxes collected from households
A steady decline in the total number of available goods for sale
A general rise in the overall prices of goods and services across the economy
A noticeable drop in the number of people earning regular paychecks