Answer:
Now in the question we are told to choose our on function so for this solution the function which we will use is

In this function D is the distance in meters which is been traveled at a given time t in seconds
Now it we want to obtain the distance traveled in t = 13 s
This means that t = 13 s is the input of the function
So we have

=> 
So D is a function of t
Now let consider one of the functions given in the question
The circumference of a circle is a function of diameter.
Generally the circumference of a circle is mathematically represented as

Here
is constant with value
and d is the diameter (in meters) of the circle so
if for example d = 0.2 m , here the diameter is the input
Then the circumference is
Step-by-step explanation: