Answer;
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Step-by-step explanation:
For a relation to be a function, no single domain value (x-value) will have two range values (y-values).
However, we can have one range value (y-value) having two domain values (x-values)
Now, with this in mind, let us check through the given options.
Let us take a look at the last option;
A single domain value 1 has two range values in (1,1) and (1,2)
This does not follows the rule, and we can assume that the given relation is not a function