This question tests the evaluation of a function at specific points and finding the input for a specific output, based on the function definition provided in Exercise 2.3 of the textbook. Parts (i), (ii), and (iii) require direct substitution of the Celsius value into the function rule, similar to the method used in Question 3 of the same exercise. Part (iv) requires setting the function equal to 212 and solving the resulting linear equation for C, a process consistent with solving linear functions described in the 'Miscellaneous Examples' and section 2.4.1.