Answer:
option A, C and D
Step-by-step explanation:
Each relation is a function if each input has only one output
{a, 1), (6, 1), (C, 1)
This relation is a function because each input has only one output
{a, a),(a, b),(a, c)}
This relation is not a function because input 'a' has only three output
{(1, a), (2, a),(3, a)}
This relation is a function because each input has only one output
{a, a), (b, b), (C, c)}
This relation is a function because each input has only one output
