On May 18, 1980, a massive eruption of Mt. St. Helens in Washington State sent a huge plume of ash more than 50,000 feet into the air. Over the next two weeks, the ash traveled around the world. To move that far, the ash would've had to:_____.
a. reach into the stratosphere.b. dissolve in the nitrogen of the air.c. bind to aerosols in the lithosphere.d. combine with moisture in the troposphere.