The correct option is C Increase the investment expenditure in the economy
If the interest rate is decreased in an economy, people will deposit less money in the banks since they would not get high returns and borrow more money with a low-interest rate, hence money supply in the economy will increase. Decrease in interest rate in an economy will increase the money supply, thus increasing the investment expenditure. With low interest rates, the banks will have more leverage to lend money to businesses and to citizens to purchase household items or to invest in productive things. With this, option A is correct as if the interest rate is decreased, then there will be an increase in investment expenditure in the economy.