Answer: Option (b) is correct.
Step-by-step explanation:
Correct option: Less money, so they lend more, and the interest rate falls.
When there is a decrease in the price level and other things remains constant, then as a result people are holding less money. This will increase the willingness of people to lend more, as a result there is a reduction in the interest rate. This fall in the interest rate will increase the money supply in the economy.