Which of the following must be an integer if the integer x…

Which of the following must be an integer if the integer x is divisible by both 28 and 21?

This problem repeats another one in the library (at most with different numbers), so it's left out of browsing.

AQuA-RAT — Algebra Question Answering with Rationales (Ling et al., DeepMind, 2017) · train #11763