Final answer:
Boston merchants announced a boycott of British goods to protest the impact of British imperial policies on Massachusetts' economy, including duties and trade restrictions. The correct option is D.
Step-by-step explanation:
The Boston merchants decided to announce a boycott of British goods to protest the effect of imperial policies on the Massachusetts economy. They were motivated by the scarcity of money, the heavy burden of taxes to pay off war debts, and the restrictions imposed by the Townshend Acts.
These policies included duties on imported goods, which led to higher costs for the merchants and scarcity of currency, and they impacted the colonial trade significantly. Additionally, the increase in British military presence in Boston and the actions of the vice-admiralty courts undermined the autonomy and economic well-being of the colonists.