Income reaches the highest level at the _ point of the business cycle.

Income reaches the highest level at the peak point of the business cycle.

The highest point of the business cycle is called peak. It follows the boom, (a protracted period in which the economy activity increases called upturn), and it is followed by a downturn, during which the amount of economy activity decreases.

So, during a peak, incomes, purchases, investment, spending and employment reach their highest point since the economy has expanded.