The correct option is: 1.) attritition
Grant was the first general of the Union to initiate coordinated offensives in multiple scenarios. While his subordinates William Tecumseh Sherman and Philip Sheridan marched through Georgia and the Shenandoah Valley respectively, Grant personally supervised the Overland Campaign in 1864 against General Robert E. Lee's army in Virginia. He used the war of exhaustion against his opponent, leading a series of large-scale combats with great casualties that alarmed the public while on his way to the Confederate capital, Richmond. Grant announced that he would "fight in this line so it will take him all summer." Lincoln supported his general and replaced his losses, Lee's waning army was forced to defend itself in the trenches around Richmond and Petersburg. In April 1865, Grant's army, vastly larger than his opponent's, attacked, capturing Richmond, and forcing Lee to surrender at Appomatox. J. C. Fuller described him as "the best general of his time and one of the best strategists of anybody". Your Vicksburg campaign in particular has been studied by military specialists from around the world.