Final answer:
Lincoln sent Grant and Sherman south to command Union forces in the Western Theater and to engage in a strategy of total war, characterized by Sherman's March to the Sea, aimed at destroying Confederate resources and breaking their will to fight.
Step-by-step explanation:
President Abraham Lincoln sent Generals Ulysses S. Grant and William Tecumseh Sherman south primarily to command Union forces in the Western Theater of the Civil War (option B). In the case of General Sherman, his March to the Sea was a strategic move to devastate Southern resources, with the objective of destroying military and civilian resources wherever possible (option A from the reference question).
This approach was part of a larger strategy of total war adopted by the Union, which sought to break the Confederacy's will to continue fighting. While Grant did not immediately accompany Sherman on the march, he was involved in simultaneous efforts in the Eastern Theater, engaging Lee's forces in Virginia.
These campaigns were designed neither to negotiate peace directly (option A), nor to establish a new government (option C), nor expressly to gather intelligence (option D). Instead, they were aggressive military strategies aiming to bring the war to Confederate territory, undermine the Confederate war effort, and force a conclusion to the conflict.