#12 - Vitamin XYZ has long been a favorite among health food

[Dave Killoran]

Is it a Must Be True or a Most Strongly Supported?

It's both, because MSS is a subclassification of Must. So, we classify all MSS as Must since that's the baseline of performance you want to look for in answers. The MSS aspect often has no effect, but occasionally "loosens" the level of certainty needed for an answer. If you see any lessening of force in the question stem (such as the "most" here), then you know you have a bit more room to play with.

Thanks!