Final answer:
The diagonal of the box is √43 ft.
Step-by-step explanation:
The diagonal of a box can be found using the formula for the diagonal of a right-angled triangle:
√(length² + width² + height²).
In this case, the length is 5ft, the width is 3ft, and the height is 3ft.
Plugging these values into the formula, we get: √(5² + 3² + 3²) = √(25 + 9 + 9) = √43 ft.
However, none of the given answer choices match this value. Therefore, none of the options provided are correct.