Help please Which kind of grapéis always a function?A) An equation with an exponent B) A circle with a center ( 0,0)C) A parabola that opens to the right D) A parabola that opens upwards

Help please Which kind of grapéis always a functionA An equation with an exponent B A circle with a center 00C A parabola that opens to the right D A parabola t class=