The correct answer is: B. enough
The word “enough” is used to describe the amount of something that is needed or desired. In this case, the parents have spent enough money on their son’s wedding. This means that they have spent the amount of money that they needed or wanted to spend.
The other options are incorrect because they do not accurately describe the amount of money that the parents have spent. The word “many” is used to describe a large number of things. In this case, it would not be accurate to say that the parents have spent many money on their son’s wedding. The word “few” is used to describe a small number of things. In this case, it would not be accurate to say that the parents have spent few money on their son’s wedding. The word “the few” is used to describe a specific number of things. In this case, it would not be accurate to say that the parents have spent the few money on their son’s wedding.