B) to exchange it for Havana.
In 1763, at the end of the Seven Years' War, Spain gave Florida to the British in exchange for Havana, which the British had captured from Spain during the war. This was part of the Treaty of Paris, which ended the war and redrew the boundaries of colonial territories in North America.
Spain's decision to give up Florida was influenced by several factors, including the fact that the territory had been a drain on Spain's resources and had been difficult to defend against the British and other European powers. By exchanging Florida for Havana, Spain hoped to regain control of a valuable colonial possession and to strengthen its position in the Caribbean. The British, for their part, were eager to acquire Florida as a valuable addition to their North American colonies.