Answer:
a. The function is increasing for all real values of x where  x < –4.
Step-by-step explanation:
Let me help you, I have answered this question once in Brainly as well 
Given the factored form of the function:
f(x) = -(x + 6)(x+2)
<=> f(x) = 
 
We will convert to vertex form 
 
Let analyse other possible answers:
<u>a. The function is increasing for all real values of x where  x < –4.</u>
True, because  the parameter a = - 1 so the graph open down all over its domain 
<u>b. The function is increasing for all real values of x where  –6 < x < –2.</u>
Wrong, the function decrease in the interval from –4.< x < -2 
<u>c. The function is decreasing for all real values of x where  x < –6 and where x > –2.</u>
Wrong, the function increase in the interval from -6 < x < -4 
<u>d. The function is decreasing for all real values of x where  x < –4.</u>
Wrong,  The function is increasing  for all real values of x where  x < –4.