Which statement is true This is not a function because some

Which statement is true

---This is not a function because some of the elements in the range are not associated with any element in the domain.

---This is a function.

---This is not a function because some of the elements in the domain are mapped onto the same element in the range.

---This is not a function because some elements in the domain have multiple elements in the range associated with it.

Solution

This is a function since each element of the domain of the function has a unique image in the codomain of the function. More over it is constant function