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For substance-use collection, one subject never smoked and did not drink caffeinated drinks on the assessment day. The example dataset does not include that subject. What does the guide say about an alternative tobacco non-use row?

It should be included in DM only.

It must always be included for every subject.

It is forbidden because non-use cannot be represented.

It could alternatively be included with SUOCCUR = "N" and null dosing/timing fields, with the same interpretation.