To determine which pair of functions has an x-intercept at (6, 0), you need to evaluate the functions or related information for each pair. Without specific details about functions A, B, C, and D, I can't definitively tell you which pair meets the criteria.
If you can provide the equations or graphs of the functions, I would be happy to help analyze them and find the correct pair that has the x-intercept at (6, 0).