Friedrich Hayek believed that

behaviors could be easily predicted.

individuals could not influence the economy.

the economy is simply explained through behaviors.

the economy is too complicated to apply aggregates.

The answer that completes the statement above is the last option: the economy is too complicated to apply aggregates. Friedrich Hayek is actually a known Austrian-British economist and a philosopher. What made him famous is his fundamental contributions in different aspects in psychology, economics, and political theory. To him, the application of aggregates is not easy since the economy is too complicated. Aggregate is considered to be the total amount of money paid in the rendering of services and selling of goods. The reason behind this is that economy does not function in a single and expected basis.