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.

The Siege of Boston, which began in 1775, ended when the British were forced out of the city in March of 1776.

Explanation:

The Siege of Boston began in April 1775 when the American military in New England prevented the movement of the British Troops in Boston. The containment of the British troops took eleven months before being finally removed or driven out of Boston in March 1776.

The Siege would become the starter or opening phase of what would become the American Revolutionary War against the colonial power of Britain. After eleven months of holding on to the city of Boston, the British were unable to get supplies. So, they moved out of Boston and shifted to Halifax in Nova Scotia.

Thus, the correct answer is the third option.

c

explanation: