Final answer:
The dimensions of the rectangle with maximum area that can be inscribed in a circle are equal to the radius of the inscribed circle.
Step-by-step explanation:
The maximum area of a rectangle that can be inscribed in a circle occurs when the rectangle is a square. This means that the dimensions are equal, and the length and width of the rectangle are both equal to the radius of the inscribed circle. Therefore, the correct answer is option C) The dimensions are equal to the radius of the inscribed circle.