Answer:
D. Today was the last day Max and I would walk to school together. The last day we would have lunch together.
Step-by-step explanation:
Parallelism occurs when the same grammatical structure is used throughout the text. In option D, the author repeats the same construction (the last day) to establish a melancholic tone over Max's future departure.
The rest of the choices are incorrect because either they do not possess parallelism or they do not create a sad tone.