Which of the following is a correct set of constraints for a linear programming problem ?

$x+2y ≤50, 3x+y ≤ 80, x≥0, y ≥ 0$ $x+2y ≤50, 3x^2+y^2 ≤ 80, x≥0, y ≥ 0$ $x+2y ≤50, 3x+y ≥ 80, x≤0, y ≥ 0$ $x+2y ≥50, 3x+y ≥ 80, x ≥0, y ≤ 0$

$x+2y ≤50, 3x+y ≤ 80, x≥0, y ≥ 0$