The cost of mailing a first-class letter is 0.46 cents for the first ounce and 0.20 cents for each additional ounce or portion of an ounce. The letter y represents the total cost for mailing a letter that weighs x ounces. Which type of function model would be appropriate for this situation?
a) Linear function
b) Step function
c) Square root function
d) Absolute value function
