During the final years of world war ii, how did the allies gain control of the north atlantic?
they used u-boats to sink german ships.
they used fighters to provide air support for their ships.
they used better anti-submarine technology.
they used allied submarines to defeat german ones.

C. Better anti-submarine technology

The best answer is They used better anti-submarine technology.

By the end of 1942, the Allies had discovered ways to thwart the U-boats. A key breakthrough occurred when British experts deciphered the German naval radio codes, enabling Allied convoys to steer clear of U-boats or to hunt them down. New technology also helped: sonar and radar enabled Allied ships to track submarines. The most effective tactic was to organize the ships into convoys with protective warships surrounding them. After May 1943, the U-boats were on the defensive, and Allied shipping losses fell significantly. The U-boats kept up the Battle of the Atlantic until the war’s end; when Germany finally collapsed, almost 50 submarines were still at sea, but 783 had been destroyed.

in 1803 the louisiana purchase took place, doubling the size of the country. by 1840 almost 7 million americans had migrated westward in hopes of securing land and being prosperous. the belief that settlers were destined to expand to the west is often referred to as manifest destiny.

explanation:

the second significant cause of the great migration was the desire of black southerners to escape segregation, known euphemistically as jim crow. rural african american southerners believed that segregation - and racism and prejudice against blacks - was significantly less intense in the north.