Consider the markets for ball-point pens and "rollerball" pens. Suppose that, due to an increased cost of the metal that is used in "rollerball" pens, the prices of "rollerball" pens increase. There are no other changes. What would happen to the demand schedules of both products? The demand curve for ball-point pens would _; the demand curve for "rollerball" pens would .a. Increase; not changeb. Increase; increaseC. Decrease; not changeD. Decrease; increaseE. Not change; decrease

Suppose the cost of metal used in making rollerball pens increases. This will cause the cost of production to increase. This increase in production will further lead to an increase in the price of rollerball pens. This consequently, will cause the quantity demanded to decrease. This decline in the quantity demanded will be indicated by an upward movement on the same demand curve.

As the price of rollerball pens will increase, the consumers will prefer the cheaper substitute. This will cause the demand for ball-point pens to increase.