Read the given statements and conclusions carefully. Assuming that the information given in the statements is true, even if it appears to be at variance with commonly known facts, decide which of the given conclusions logically follow(s) from the statements.
Statements:
All nieces are sisters.
Some nieces are brothers.
Conclusion:
I : Some brothers are sisters.
II : All sisters are nieces.
III : No brothers are sisters.

Conclusion: I : Some brothers are sisters.

From the above diagram, we can conclude the given conclusion follows.

Conclusion:II : All sisters are nieces.

From the above diagram, we can conclude that 'some sisters are nieces.'. But we cannot say about 'all'. So the given conclusion does not follow.

Conclusion: III : No brothers are sisters.

There is not any negative relation given between these entities. So the given conclusion does not follow.

So only conclusion I follow.