Which of the following scenarios exhibits a function relation? take the first set listed to be the domain of the relation.
the set of tree heights and the set of trees in a forest
the set of car make and models and the set of people in a certain town
the set of birthdays and the set of students in a class
the set of people with social security cards and the set of social security numbers

The scenario that exhibits a function relation is:

    The set of people with Social Security cards and the set of Social Security numbers.

We know that a function is a relation in which each element of first set has one image i.e. an element can't be mapped to two distinct elements of the other set.

a)

The set of tree heights and the set of trees in a forest.

This relation is not a function.

Since, two trees may have a same height.

b)

The set of car make and models and the set of people in a certain town.

This relation is also not a function.

Since, two people may have a car of same model.

c)

The set of birthdays and the set of students in a class

This relation is not a function since two students may share same birthday.

d)

The set of people with Social Security cards and the set of Social Security numbers.

This relation is a function.

Since, the security card number has a unique number on each car.

This means that each person has a unique card number.