Answer:
A. 
B. 
and
D. 
Step-by-step explanation:
A rational function is of the form
where
and
are polynomial functions.
Based on this definition, every polynomial function is a rational function.
Hence the rational functions in the options provided are;
A. 
B. 
and
D. 
is not a rational function because the numerator is not a polynomial function.
It's an upside (-) down parabola. The axis of symmetry is the x coordinate of the vertex.
you can easily find this using formula: x= -b/2a
for parabola: ax² + b + c = 0
x = -16 ÷ 2(-4)
x = 2
Answer C
4xa +8 =4a+8
..........................
The answer is 3 :) hope this is right