Option 1 -> exorbitant means unreasonably high or excessive, perfectly describing overspending on branded clothes.
Option 2 -> exotic means foreign or unusual, which doesn't logically describe an amount of money.
Option 3 -> exquisite means beautiful or delicate, used for quality not quantity of spending.
Option 4 -> expository means explanatory or descriptive, completely unrelated to monetary amounts.
Hence, Option 1: exorbitant -> The word "exorbitant" appropriately conveys that peer pressure causes children to spend an unreasonably excessive amount on branded clothes, which is the intended meaning of the sentence -> correct