Data Sufficiency

For the function f(x) = y = to intersect with the x - axis, y should be 0.
=> ax^2 + c = 0
x^2 = -c/a
so we will have real roots if x^2 is positive or zero.

1) a < 0
x^2 = -c/a, x^2 is positive when c is +ve
if c is -ve, we will have imaginary roots.
so can`t answer with option 1 alone.

2) c > 0
x^2 = -c/a, x^2 is positive when a is -ve.
if a is +ve, we will have imaginary roots.
so can`t answer with option 2 alone.

taking option 1 and 2.
we have x^2 = +ve, hence it has real roots. so it will intersect x-axis.

Hence, it is C