What does lincoln want his audience to do in the coming days

Lincoln had prepared this speech carefully. Though he began on a joyful note—“We meet this evening, not in sorrow, but in gladness of heart. The evacuation of Petersburg and Richmond and the surrender of the principal insurgent army, give hope of a righteous and speedy peace”—and promised a day of “national thanksgiving” he proceeded directly to a reminder that the nation now faced a task “fraught with great difficulty,” that of “re-inauguration of the national authority—reconstruction.”

i believe your answer is d)