Which of the tables represents a function? table a input output 5 3 5 2 4 1 table b input output 1 2 3 2 5 3 table c input output 0 0 1 2 1 3 table d input output 4 2 4 3 4 4

Input is domain and output is co-domain.
An expression is said to be a function if for every input, there is only one output. In table B, for every input, you get different outputs. Therefore, table B is a function. 

Table B is correct I do FLVS and just did the test and got that correct.