more than one possible answer for this?

Di,

‘ C’est le livre de Paul ‘ does not translate as ‘ a book about Paul ‘. 

You could use ‘ le livre sur Paul ‘ as a translation of ‘ the book about Paul ‘.

I can understand your confusion trying to distinguish between the 2 responses ‘ Paul’s book ‘ or ‘ book from Paul ‘ - without context, without explanation in the lesson and with standalone phrases to choose between, I think this is a poor choice to present.

 https://www.wordreference.com/fren/sur 

https://www.wordreference.com/enfr/about 

https://www.wordreference.com/fren/de