Answer:
Option A. 0.4 of an orange
Step-by-step explanation:
Formula to calculate the opportunity cost is
Opportunity cost = [tex]\frac{\text{Sacrificed}}{\text{Gained}}[/tex]
In this question for the high yield, sacrificed thing is 100 tubs of grapes and gain is to produce 250 tubs oranges.
Opportunity cost = [tex]\frac{100}{250}=0.4[/tex] of an orange
Therefore, Option A. 0.4 of an orange, will be the answer.