If k is the sum of the digits of integer m, and…

If k is the sum of the digits of integer m, and m=12n, where n is an integer, which of the following must be true?

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 #14274