Answer: A
Step-by-step explanation:
Each square has a side length of 2 units
[tex]f1 = (4*1)^{2} = 4^{2} = 16\\f2 = (4*2)^{2} = 8^{2} = 64\\f3 = (4*3)^{2} = 12^{2} = 144\\fn = (4n)^{2}[/tex]
