Final answer:
The tonality most suitable for a triumphal march is Major, as it conveys a sense of brightness and victory, matching the celebratory mood of such a piece.
Step-by-step explanation:
The tonality that would most likely be chosen for a triumphal march is Major. Major tonality is generally associated with bright, positive, and uplifting feelings which are well-suited for a composition meant to evoke a sense of triumph and victory.
Minor tonality, while it can be powerful, often carries a more somber or introspective mood. Chromatic and atonal music, with their inherent dissonance and lack of a central key, tend not to convey the straightforward celebratory character typically desired in a triumphal march. Therefore, to portray the appropriate mood of celebration and grandeur, major tonality is commonly used.