Can someone help me find the maximum or minimum value?

Answer:
(c) Minimum value is -16.
Step-by-step explanation:
This will have a minimum value because the leading coefficient is positive.
We can find the minimum value by converting the function to vertex form:
f(x) = x^2 + 4x - 12
f(x) = (x + 2)^2 - 4 - 12
f(x) = (x + 2)^2 - 16.
The minimum value is -16.
So when you draw the graph the turning point is at (-2, -16).