Which of the following is true, other things equal?

a$.$ A reduction in prices will increase profit margins and, thereby, stimulate additional investment.

b$.$ A reduction in prices will lead to a decline in net exports.

c$.$ A reduction in prices will increase the real wealth of those holding a fixed quantity of money.

d$.$ A reduction in prices will increase the scarcity of money, raise the real interest rate, and, thereby, encourage investment and consumption.