Final answer:
The most appropriate type of polynomial function for modeling the area of the rectangle with a length 6 units greater than its width is a quadratic function.
Step-by-step explanation:
A rectangle has two sides: length and width. In this case, the length is 6 units greater than the width. Let's say the width of the rectangle is 'x'. Since the length is 6 units greater than the width, we can represent it as 'x + 6'.
The area of a rectangle is given by the formula A = length * width. Substituting the values, we have A = (x + 6) * x.
Expanding the equation, we have A = x^2 + 6x. This is a quadratic equation, so the most appropriate type of polynomial function for modeling the area of the rectangle is D) quadratic.