Looks correct to me but i'm not 100% sure
Answer:
D.
Step-by-step explanation:
After the third step, take the square root of both sides.
Third Step:

Thus, the fourth step is:

The left side cancels:

D.
The area of a square is always:
A=s^2 where s=side length, in this case:
A=4^2=16 in^2
The perimeter of a square is always:
P=4s, in this case:
P=4*4=16 in