In which of the following data sets is the mean equal to the mode?
4, 4, 4, 6, 6
4, 5, 5, 5, 6
3, 3, 4, 6, 7
4, 4, 4, 6, 6
4, 5, 5, 5, 6
3, 3, 4, 6, 7