If the roots ofax^2 +bx+c= 0 are real, rational, and equal, what is true about the graph of the function

y=ax^2 +bx+c?

(1) It intersects thex-axis in two distinct points.

(2) It lies entirely below thex-axis.

(3) It lies entirely above thex-axis.

(4) It is tangent to thex-axis.