Answer: The production possibility curve of Jake will pivot on the axis of trains.
Step-by-step explanation: When there is a technological change in favor of one good, the quantity of that good produced with the same amount of resources increases. This means that there will be more trains being produced using the same amount of resources. While, there is no change in the quantity of the of balls being produced.
Since there is no change in the quantity of balls the horizontal axis will not change.