Food labeling regulation: Food of a type that does not ordinarily contain fat cannot be labeled "nonfat" unless most people mistakenly believe the food ordinarily contains fat.
Given
Food of a type that does not ~OCF + ~MBF → ~LN ordinarily contain fat cannot be labeled “nonfat” unless most people mistakenly believe the food ordinarily contains fat.
If most people mistakenly MBF and LFO → may LN believe that a food ordinarily contains fat, the food may be labeled “nonfat” if the label also states that the food ordinarily contains no fat.
Evaluate
The labeling regulation presents two conditional relationships. The right answer will violate one of them. Since the second rule is wishy-washy (it's just saying you MAY do something), it would be hard to contradict. To contradict it, we'd need to hear that someone CAN'T label their food nonfat. Simply saying they AREN'T labeling their food nonfat wouldn't contradict it.
So we can anticipate that the correct answer will break the first rule.
It'll give us something that - doesn't ordinarily contain fat and - isn't something ppl wrongly think does contain fat
and this food will be getting labeled nonfat, thereby breaking the rule.