Answer:
"The coefficient of x²-term must be positive"
D is correct
Explanation:
Given:

We are given a quadratic equation. The quadratic equation whose degree is 2.
The leading coefficient of quadratic can't be 0.


The highest degree should be 2
For quadratic formula:

First we make right side 0 and then apply quadratic formula.
Hence, The condition which is not true for quadratic formula "The coefficient of x²-term must be positive"