Final answer:
The execution of Mary, Queen of Scots, was the final event that led Philip II of Spain to launch the Spanish Armada against England in 1588, seeking to dethrone the Protestant Queen Elizabeth I and restore Catholicism.
Step-by-step explanation:
The final straw that convinced Philip II to send the Armada against England was the execution of Mary, Queen of Scots (C), her cousin and the Catholic heir to the throne of England. Philip II of Spain, who was the widower of Mary I of England, saw the execution in 1587 as an attack on Catholicism and a direct challenge to his desired influence over England. This act against Mary, who was a strict Catholic and a potential Catholic monarch for England, removed a key ally for Philip, leading him to attempt to overthrow Elizabeth and reassert Catholic dominance with the Spanish Armada.Philip's motivations were influenced by multiple factors, including the religious turbulence of the time, his personal and political losses, such as the rejection by Elizabeth and the deteriorating economic condition of Spain. He saw the Protestant Reformation as a threat to Catholic hegemony and viewed the removal of Mary, Queen of Scots, as an attack on this hegemony. However, the Spanish Armada's defeat, viewed by Elizabeth as aided by a “Protestant wind,” ensured the preservation of Protestantism in England.