C
one way to solve is to use the method of completing the square
subtract 3 from both sides
x² - 2x = - 3
add ( half the coefficient of the x-term )² to both sides
x² + 2(- 1 )x + 1 = - 3 + 1
(x - 1)² = - 2
take the square root of both sides
x - 1 = ± √(- 2) = ± i√2 ( add 1 to both sides )
x = 1 ± i√2 → C