Answer:
D
Step-by-step explanation:
given a quadratic equation in standard form
ax² + bx + c = 0, then the discriminant is
Δ = b² - 4ac
x² + 3x - 4 = 0 ← is in standard form
with a = 1, b = 3, c = - 4
b² - 4ac = 3² - (4 × 1 × - 4) = 9 - (- 16) = 9 + 16 = 25 → D
