A standing desk has 31 height settings, numbered from the lowest height, 1 , to the highest height, 31 . Since the desk is not working properly, when the up button is pressed, the desk goes up 6 settings at a time if possible, otherwise it does not move. When the down button is pressed, the desk goes down 4 settings at a time if possible, otherwise it does not move. If the desk starts at setting number 1, how many of the 31 settings will the desk be able to stop at?
Answer Choices
A. 14
B. 16
C. 9
D. 15
E. 10