Answer:
Option D.
Step-by-step explanation:
Let y represents the time in hours and x be the average speed of train in miles per hour.
We know that

It means time is inversely proportional to speed.

.... (1)
where, k is the constant of proportionality.
From the given table it is clear that the value of time is y=5 at speed x=32.
Substitute x=32 and y=5 in the above equation to find the value of k.

Multiply both sides by 32.


The value of k is 160.
Substitute k=160 in equation (1).

The rational function models
the time, y, in hours, that it takes the train to travel between the two cities at an average speed of x miles per hour.
Therefore, the correct option is D.