Betsy overheard a heating contractor say that regularly changing the filter in a furnace helps to keep the furnace efficient. So Betsy has regularly
Why this is right
1. have evidence X will benefit others Yes? - she heard a heating contractor say "doing X helps to keep the furnace efficient". 2. do X to benefit others Yes? Betsy is presumably changing her daughter's furnace filter to benefit her daughter. The connector "So" helps to convey that "hearing that this would make the furnace be more efficient" is the reason that "Betsy is doing this action". 3. X helps others Yes - doing this action has benefited the daughter, in the sense that the daughter's furnace has never needed maintenance. This answer strikes me as somewhat lacking, since it's not explicit in establishing that the mom is changing filters for the daughter's benefit, but it's a highly plausible common sense interpretation. Similarly, the outcome is a furnace that has required maintenance due to clogging. That's a weak match for the idea of "benefiting others", but again it makes plausible common sense that it benefits you if your furnace doesn't require maintenance.
Skill tested: Principle-Conform · how this choice captures the argument's function is the move to repeat next time.