Answer:
D) Quantity sold rose while the effect on price is ambiguous.
Step-by-step explanation:
Two separate things happened here;
- Change in consumer habits have shifted the the demand curve to the right, increasing the quantity demanded at every price level.
- Better technology and lower costs have also shifted the supply curve to the right, increasing the quantity supplied at every price level.
One thing is certain, the quantity demanded and supplied increased, so the total quantity sold definitely increased. The price issue is not certain because you would need additional information about which shift was larger, the shift of the supply curve or the demand curve.