So your equation is x^2 - 2x, and you want to find the values of x for which its y values are less than 0, aka negative.

So let's set the equation equal to 0 to find it where it's on the x-axis ---> x^2 - 2x = 0

Factoring out gives you --> x(x-2) = 0

x will equal 0 and 2 --> (0,0) and (2,0) are the points of this parabola that lie on the x-axis.

The coefficient for the x^2 term determines whether a parabola will be opening upward (positive) or downward (negative)--- (we know it's a parabola because the highest term is X^2; if it was a line, it would be just x^1 aka x).

For this equation, the coefficient is just 1 and it is positive --> the graph opens upwards in a "U" shape.

Now we know what points on it hit the x-axis, and we know its shape. Now we can determine where it will be negative (this will be below the x-axis). So, the equation is negative (aka < 0) between the values of 0 and 2, leading to C being your answer.

Here's a graphical representation. The question basically wants you to find the values of x that bound the area I shaded in yellow (as this is where the equation is less than 0 aka negative). Hope this helps! Let me know if you need any explanations on something I said.