GMAT Verbal Section | PROBLEM REGARDING QUESTION STEM

hey..
actually i wasn't able to find a place where I could place my question so I am asking here..

It may appear silly..but I have been having this doubt for awhile...
Which of the following,if true most supports the argument?

This is the common question stem which we encounter for both the strengthen and Must be true questions

How will we get to know that whether we can Strengthen the question by using outside information(way to strengthen the questions)
OR
we have to to select that option
...

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