Final answer:
The Scheme expression evaluates to 90 after performing the operations within the let statement. So the correct answer is option D.
Step-by-step explanation:
The result of the Scheme expression (let ((x 10) (y 10)) (- (* x y) y)) is calculated by first evaluating the multiplication of x and y, and then subtracting y from the result. Since both x and y are bound to the value 10, the multiplication (* x y) equals 100. Then, you subtract y, which is 10, to get the final result, which is 90. Therefore, the correct answer is D) 90.