Regression anaylsis was applied between demand for a product (Y) and the price of the product (X) and the following estimated regression line was obtained; Y = 120 - 10X. Based on the above regression equation, if the price is increased by 2 units, then the demand is expected to
a decrease by 100 units
b increase by 100 units
c increase by 20 units
d decrease by 20 units
e none of the above