Answer:
C
Step-by-step explanation:
ROC is often used when speaking about momentum, and it can generally be expressed as a ratio between a change in one variable relative to a corresponding change in another; graphically, the rate of change is represented by the slope of a line.
The 63 is the err in her explanation here.
The discriminant is

which is 0.
Since the discriminant is 0, there is only one real solution.