Final answer:
In function notation for the given relationship where a circle's position changes with the height of a rectangle, the height of the rectangle would be the independent variable and hence, placed inside the parentheses.
Step-by-step explanation:
In function notation, the variable inside the parentheses typically represents the independent variable, which is the input of the function. Given the description that the position of the circle changes according to the height of the rectangle, the height of the rectangle is the independent variable. Therefore, if we were to represent this relationship in function notation, the height of the rectangle would be located inside the parentheses. So, the correct answer is A. Height of the rectangle.