Select the most appropriate option to fill in the blank.

The country's rapid _____ has led to a rise in many people's standard of living.

growth

The most appropriate option to fill in the blank is growth.

The sentence is about the positive impact of economic growth on people's standard of living. The word "growth" means an increase in size, number, or amount. It is the most appropriate option because it conveys the idea that the country's economic growth has led to an increase in the standard of living for many people.

The other options are incorrect.

• Idea does not make sense in this context.
• Life does not make sense in this context.
• Confidence does not make sense in this context.