This question could be called Linear vs Exponential as it asks for linear with fancy wording: “equal difference over an equal interval”(as opposed to just the word linear)

(I)  3.5 cm a day would make the y values go up 3.5 each day this is linear

(II) depreciate 15% a year is exponential

(III) tripling is exponential
see #25 on this Regents for long answer of linear or exponential!!