THE SECOND ANSWER IS THE CORRECT FORM TO USE.

The 'have been tired' in the second sentence is correct but the 'in' before 'these weeks' isn't necessary. Either 'they have been tired these weeks' or even better sounding would be 'they have been tired these last few weeks' (at least in the US). Hope that helps, Andrew

Neither sounds good. We would say something like 'in recent weeks' or 'in the last few weeks' instead of 'these weeks'. While you will be understood it would never be said as you have said it by a native speaker.