Answer:
![V=2x^2+8x+8](https://img.qammunity.org/2021/formulas/mathematics/high-school/8l2kjrb6rg42ujgv0epbd606ytwgc66ywn.png)
Explanation:
The volume of a right rectangular prism is given by :
![V=lbh](https://img.qammunity.org/2021/formulas/chemistry/college/algyblh5yqj9k1w0s78kvnzqz607og1985.png)
Where,
l is length, bis breadth and h is height
ATQ,
Height of the cage is 2feet
The length and width are both x feet more than the height.
l = b = (x+2)
So,
![V=(x+2)(x+2)2\\\\V=(x+2)^22\\\\V=(x^2+4+4x)2\\\\V=2x^2+8+8x](https://img.qammunity.org/2021/formulas/mathematics/high-school/xg5xbuvjdu2p5k4lx3mrze6wi3pydjt9d5.png)
So, the correct option is (D).