Looking at the table below, which answer best explains the data shown?

question 4 options:

this is a function because each output (y-value, range) is unique

this is a function because each input (x-value, domain) is matched to exactly one output (y-value, range)

this is a relation only because 4 is input twice and has 2 different output values

this is a relation only because each output value is unique