Passage Summary: Tanya says she'll stop littering if every single person on Earth stops; her friends don't litter, so we assume Tanya has stopped too.

Conclusion: Tanya does not litter.

Reasoning: Tanya would stop littering if every single person also stopped; since her friends do not litter, it is concluded that she does not litter either.

Analysis: The flaw here is a scope error involving a conditional statement. Tanya's requirement for not littering is that 'everyone else' refrains, but the evidence provided only mentions 'her friends.' Her friends are just a small subset of 'everyone.' The argument fails because it assumes that what is true of a small group (the friends) is true of the entire population (everyone). To match this flaw, look for an answer that takes a condition based on a whole group and tries to satisfy it using only a specific part of that group.