hey guys I have a hard question for my college pre help I have done this question but I want to see if you can get it

Replacing F with F + 1 gives

5/9 (F + 1 - 32) = 5/9 (F - 32) + 5/9 = C + 5/9

so a temperature increase of 1º F translates to a 5/9º increase in Celsius, so I is true.

Replacing F with F + 5/9 gives

5/9 (F + 5/9 - 32) = 5/9 (F - 32) + (5/9)² = C + 25/81

so increasing the temperature by 5/9º F amounts to a 25/81º increase in Celsius, so III is false.

Solve for F in terms of C :

F = 9/5 C + 32

Replacing C with C + 1 gives

9/5 (C + 1) + 32 = 9/5 C + 32 + 9/5 = F + 9/5

and 9/5 = 1.8, so a 1º C increase translates to a 1.8º F increase, so II is also true and the answer is D.