Helen: It was wrong of my brother Mark to tell our mother that the reason he had missed her birthday party the evening before was that he had been in a traffic accident and that by the time he was released from the hospital emergency room the party was long over.
Conclusion
It was wrong for my brother Mark to tell our mom that he missed her birthday party because he got into an accident and didn't get out of the hospital in time. (jeeez, Mark, try a smaller lie next time)
Evidence
Saying something false is always wrong, and what Mark said was false (there was no accident).
Evaluate
When we Do Main Conclusion and Role questions, we prime our brains before we start reading the paragraph -- remember, they love to have the Conclusion appear earlier than the Evidence, so listen for an opinion from the author that then gets supported.
Seeing the opinionated wording "it was wrong" as the first three words out of the gate would make us suspect that the first sentence is going to end up being the Main Conclusion. Does the author proceed to try to convince us that what Mark did was wrong?
Sure, she defines a principle that allows us to say an action is "wrong" and then establishes that this principle applies to Mark.
Also, the 2nd and 3rd claims in this argument (comprising the 2nd sentence) are joined by "and", and 99% of the time that two claims are joined by "and", they are both premises.
Goal
Look for an answer choice that matches the conclusion, the first sentence of the paragraph.