What Event Galvanized the Cause of Irish Nationalism During World

What event galvanized the cause of Irish nationalism during World War I?

A) the British government's blunt refusal to consider "Home Rule" until after the war
B) the execution of the leaders of the Easter Rebellion in 1916
C) the founding of the Sinn Fein political party
D) the appalling losses among Irish soldiers during the Somme offensive
E) the outspoken support for Irish independence by the prince of Wales