Final answer:
In December 1864, General William T. Sherman captured Savannah, Georgia and presented it to President Abraham Lincoln as a Christmas gift.
Step-by-step explanation:
In December of 1864, Major General William T. Sherman completed his military campaign through the South, known as the March to the Sea, by capturing the key coastal city of Savannah, Georgia. After the city's Confederate defenders, under Lieutenant General William J. Hardee, withdrew and Mayor Richard Arnold surrendered the city on December 22, Sherman famously sent President Abraham Lincoln a message, declaring Savannah to be his 'Christmas gift.' The event marked the end of Sherman's March and set the stage for his subsequent campaigns into the Carolinas.
As the correct answer to the student's question: In December of 1864, William T. Sherman wired Lincoln that he was presenting a Christmas gift of the port city of Savannah (Option B).