opportunity cost

opportunity cost = highest valued option forgone
if he choose Italian food

the rest(Chinese food and Thai Food)~~~forgone
according to his preference, the priority of Chinese food was higher than Thai food.
Therefore, execept Italian food, he would prefer to it Chinese food more than Thai food.
under the definition of the theory, Chinese food should be the highest valued option forgone.

so that, opportunity cost= Chinese food

Highest option forgone.--->So the answer should be 1) Chinese food

Happy Family
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