Which is the parent function of a parabola?

Question

1 f(x)=x

2 f(x)= 2X+1

3 f(x)=-x^2+ 3

4 f(x)=x^2

Answer 1

The parent function of a parabola is the function of a quadratic with no transformations done to it.

Option 1 & 2 are both linear functions and would be incorrect

Option 3 is a quadratic function but has a reflection and an upward shift so also incorrect

Leaving Option 4 which again is a quadratic function with no transformations to it.