what is the range of the function?

The range is the second set: {2, 4, 9, 16}
Answer: D.
First set is the domain.
Option: D is the correct answer.
The range of the function is:
{2,4,9,16}
We know that a range of a function is the set or collection of all the values that are attained by a function.
i.e. it is the image of the element that belong to domain.
From the Mapping diagram that is provided to us we observe that:
1 is mapped to 2.
2 is mapped to 4.
3 is mapped to 9.
4 is mapped to 16.
Hence, the range of the function is:
{2,4,9,16}