Your answer is the first option, (9 - 5)/(4 - 0). This is because the formula to finding the slope of a line is (y2 - y1)/(x2 - x1), and the first option has the two y coordinates subtracting and the two x coordinates subtracting. I hope this helps!
A graph shows the limit to be 1/2. https://www.desmos.com/calculator/qrf6ay47tw
Since the value of the function is the indeterminate form 0/0, L'Hôpital's rule applies. The ratio of derivatives of numerator and denominator is .. x/ Evaluated at x=1, this is .. 1/ = 1/2