The best explanation for why the end of salutary neglect made the American colonies angry is:
The colonies had gotten used to being able to trade with whoever they wanted and paying lower taxes.
This response highlights how the colonies had developed a certain level of autonomy in trade and taxation during the period of salutary neglect. When the British government began to enforce stricter trade regulations and taxes after the end of this period, the colonies were frustrated because they were accustomed to a more independent economic system. This shift created resentment and contributed to rising tensions between the colonies and Britain.