The parabolic graph represents a quadratic equation.

I : The graph passes through II & III quadrant, so when x is negative, y can be either positive or negative.

II : The graph passes through I & IV quadrant, so when x is positive y can be either positive or negative.

III : For each value of y, there can be either one or two corresponding values of x.

IV : As the graph is an upward parabola, thus with increase in x, y is also increasing.

=> Thus, none is true.