Based on the Concept of Supply and Demand Driving Changes

Based on the concept of supply and demand driving changes in the cost of money (interest rates) , which of the following changes in the economy will tend to increase interest rates?

A) Investors have decided to save a higher percentage of their income.
B) Business in general is finding fewer opportunities to expand their operations.
C) Investors are insecure about the economy.
D) Both b and c will tend to increase interest rates.
E) All of the above will tend to increase interest rates.