I believe the answer is A
You are given the function 
Express t:

This expression gives the month t in terms of the price p.
Standard form: y = x^2 + 10x + 21
Axis of symmetry: x = -5
X intercepts: (-3,0) (-7,0)
Y intercepts: (0,21)
Vertex: (-5,-4)
Answer:
5. 4(4a-b)
Step-by-step explanation:
i hope this helps :)