The correct answer is D.
Step-by-step explanation
A production possibility curve is a way of graphically expressing the maximum production possibility. According to the above, if Playland has 120 workers and each one can produce 6 horseshoes or 3 hand grenades, the production possibility curve would have to be used to express the maximum number of hand grenades and horseshoes that its workers can produce.
To know what is the maximum production possibility capacity, it is necessary to multiply the 120 workers by 3 (in the case of knowing which is the maximum possibility of production of hand grenades) or by 6 (in the case of knowing which is the maximum possibility of production of horseshoes).
Therefore, the maximum possibility of grenade production is
120 x 3 = 360.
And in the case of the maximum possibility of production of horseshoes is
120 x 6 = 720.
So the correct answer is D because it is the only graph that expresses these possibilities correctly.