Question

the siege of boston, which began in 1775, ended when the continental army left boston in march of 1776. the british allowed supplies into the city in march of 1776. the british were forced out of the city in march of 1776. the olive branch petition was sent in july of 1775.

Explanation:

The Siege of Boston ended when the British, under pressure from the Continental Army, were forced to leave the city in March 1776. The Olive - Branch Petition is unrelated to the end of the siege, and the other options about the Continental army leaving or the British allowing supplies are incorrect.

Answer:

the British were forced out of the city in March of 1776.