This Quiz focuses on 'these Questions of ours', as examples of expressing Demonstratives ('this/that' etc.) and Possession, in various combinations ~ so as to make sure you can pinpoint items and their owners, in order to avoid any potential embarrassment.
Meanwhile you would not ask permission to borrow anything except from its owner, so Answer 4 has to be right as it is the only one referring to 'yours'.
The books are more likely to be 'these' (that we've picked up, and like the look of) than 'those' (further away; less attractive or involved).