The equation above shows how temperature f, measured in degrees fahrenheit, relates to temperature c, measured in degrees celsius. based on the equation, which of the follow must be true?

Check the complete question attached. 

We have the equation equation (1); solving for F we get: 


equation (2)

I. To check this we are going to use equation (1) to see what hapen when temperature rises from 32 Fahrenheit  to 33 Fahrenheit:
For 32 Fahrenheit:


 

For 33 Fahrenheit:


 
Now we are going to subtract the two temperatures in degrees Celsius:
As you can see, the temperature increased  degree Celsius.  

We can conclude that a temperature increase of 1 degree Fahrenheit is equivalent to a temperature increase of  degree Celsius. 

II. To check this one we are going to use equation (2) to see what happens when temperature raises from 1 degree Celsius to 2 degrees Celsius:
For 1 degree Celsius:





For 2 degrees Celsius:




Now we are going to subtract the two temperatures in Fahrenheit: 
As you can see, the temperature increased 1.8 Fahrenheit. 

We can conclude that a temperature increase of 1 degree Celsius is equivalent to a temperature increase of 1.8  Fahrenheit.

III. Since a temperature increase of 1 degree Fahrenheit is equivalent to a temperature increase of  degree Celsius, we can conclude that this one is false. 

The correct answer is D) I and II only