A relation can be regarded as a function if the x values are unique for every y-value.
The relation (option d) represents a function
(a) The table
The table has the same x-values for y values of 7 and 1.
i.e
Hence, the table is not a function
(b) The graph
The graph has the same x-values for y values of -5 and 1.
i.e
Hence, the graph is not a function
(c) The ordered pair
The ordered pair has the same x-values for y values of 2 and 4.
i.e
Hence, the ordered pair is not a function
(d) The relation
For every y-value, there is a corresponding and unique x-value.
Hence, the relation is a function
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