Correct Option: C

Yuri Alekseyevich Gagarin was a Soviet pilot and cosmonaut. He was the first human to journey into outer space and the first to orbit the earth, when his Vostok spacecraft completed an orbit of the Earth on 12 April, 1961. Vostok 1 marked his only spaceflight, but he served as backup crew to the Soyuz 1 mission (which ended in a fatal crash).