Final answer:
The answer is option A. The Sons of Liberty were formed to protest the Stamp Act of 1765, participating in dramatic protests against taxation without representation.
Step-by-step explanation:
The Sons of Liberty were formed primarily to protest the Stamp Act of 1765. This act mandated that many types of printed materials in the colonies be produced on stamped paper from London, carrying an embossed revenue stamp. The Sons of Liberty organized and participated in protests against this act, which they saw as an unconstitutional form of taxation without representation. Activities such as the hanging and beheading of a stamp commissioner in effigy were among their notable forms of protest. The Stamp Act was one of several measures imposed by Britain, including the Sugar Act of 1764 and Townshend Duties, aimed at dealing with the debt from the Seven Years' War but ultimately led to increased colonial disaffection.