Answer:
The correct answer is attainable and efficient.
Explanation:
The production possibility curve or frontier shows a different combination of two goods that can be produced using the fixed resources. Each point on the production possibility curve shows the bundles of good that are productively efficient and attainable.
The points below the curve show those bundles which are attainable but productively efficient. The points above the production possibility curve show those bundles which are not attainable because they require more resources. The point where the PPF intersects the vertical axis is both productively efficient as well as attainable.