Option D is incorrect. The discriminant of $x^2 - 3x + 4$ is $b^2 - 4ac = 9 - 16 = -7 < 0$, so this polynomial has no real zeroes. None of the given options is correct.
(If forced to choose from the options as given, none is correct.)
Source: Chapter 2, Section 2.3
---
The discriminant $D = b^2 - 4ac = (-3)^2 - 4(1)(4) = 9 - 16 = -7 < 0$ means the parabola does not intersect the x-axis, so there are no real zeroes (Case iii from Section 2.2). This is a trick/error question — examiners sometimes test whether students blindly match options or actually verify. If this appears on a real paper, write the discriminant calculation and state no real zeroes exist. Check options by substituting: none of the pairs satisfies the polynomial.