**Correct option (b) atleast two real roots **

**Explanation:**

ac ≠ 0

ac > 0 or ac < 0

Now D_{1} = b^{2 }– 4ac & D_{2} = d^{2}+ 4ac

When ac > 0

D_{2 }> 0 but D_{1} may positive or negative

When ac < 0

D_{1} > 0 but D_{2} may be positive or negative

In either case the polynomial has atleast two real roots