In a function, for every number for 'x' there is only one 'y'. So, if you have two ordered pairs in a choice that have the same number for 'x', that is not a function.
Remember an ordered pair is written (x, y).
B is not a function as: (x, y) (1, -2) (1, -3) (1, -4) ^ All of the x-coordinates are the same.
E is not a function as: (x, y) (6, -1) (6, -8) ^ Two of the x-coordinates are the same.