Final answer:
The phrase 'One if by land, two if by sea' is associated with lanterns hung in the steeple of the Old North Church in Boston, indicating the approach of British forces.
Step-by-step explanation:
The warning phrase 'One if by land, two if by sea' refers to the signal system used by Paul Revere during the American Revolution to alert the colonial militia of the approach of British forces before the battles of Lexington and Concord. The lanterns were hung in the steeple of the Old North Church in Boston to signal the route the British troops chose to advance. The correct answer to the student's question is A) Old North Church.