The diagrams concern industry X. P5 is the starting production possibility curve. Manufacturing techniques in industry X improve. Which changes occur?
- Aaverage costs: ATC1 to ATC2; market for X: S3 to S4; new production possibility frontier: P7
- Baverage costs: ATC1 to ATC2; market for X: S4 to S3; new production possibility frontier: P6
- Caverage costs: ATC2 to ATC1; market for X: S3 to S4; new production possibility frontier: P6
- Daverage costs: ATC2 to ATC1; market for X: S4 to S3; new production possibility frontier: P7