Which of the following is considered a best practice when accessing FSO from a mobile device? A. Connect your mobile device to Wi-Fi

B. Have a mobile device that was released in the last two years

C. Install the latest operating system that your mobile device can support

D. All of the above

The highest point of a hill (or mountain) is a single point.
a single point can only be precisely marked with a dot. 
putting on a contour line is impossible  on a single point because the contour line is created after multiple points that have the same hight are marked, and after that, all of those points are connected with a line that creates a closed area. so the highest point, as said above, is a single point, there are no other points with the same height, so the only possible way for it to be marked is with a dot, and there is no possibility for a contour line.