Milton Friedman argued that consumers are more likely to alter their behavior based on changes in the unemployment rate.
short-term changes in the economy.
long-term changes in the economy.
changes in the inflation rate.

long-term changes in the economy.

Explanation:

Milton Friedman gave a economic theory called monetarism, that refer to the control of money in the economy. Friedman gave an idea that changes in the money supply have long-term and short term effects.

Friedman argued that consumer behavior is influenced by the long-term changes in the economy. Long term changes in economy influence consumer behavior in spending money for their goods. for example: If  Long term changes in economy are positive then the consumption by consumers increases otherwise it will decrease.

Hence, the correct answer is "long-term changes in the economy."