Macroeconomics focuses on economy-wide policies and aggregates

Steps:

• Define macroeconomics as the study of overall economic performance, including government fiscal policies.
• Examine each option for its scope: does it affect the entire economy or just a small part?
• Distinguish from microeconomics, which covers individual or sector-specific behaviors.
• Identify the option involving broad government intervention as macroeconomic.

Why B is correct:

• Income tax increases are a fiscal policy tool that affects aggregate demand and national income, per Keynesian economics.

Why the others are wrong:

• A: Reflects individual household decisions, a microeconomic behavior.
• C: Involves wages in one industry, a microeconomic labor market change.
• D: Concerns prices of a single commodity, a microeconomic supply shock.

Final answer: B