Correct option (b) atleast two real roots
Explanation:
ac ≠ 0
ac > 0 or ac < 0
Now D1 = b2 – 4ac & D2 = d2+ 4ac
When ac > 0
D2 > 0 but D1 may positive or negative
When ac < 0
D1 > 0 but D2 may be positive or negative
In either case the polynomial has atleast two real roots