When we say that a difficult situation has a silver lining, it means that something positive or good can come out of it. The text provides evidence of this in respect of unemployment, both for the individual and for society. These positive outcomes are the unexpected but welcome consequences of what, otherwise, is a disaster.
The idiom, in full, is 'Every cloud has a silver lining' and, while this may be overly optimistic - not every bad situation has good incidental effects - it's a call to look for something 'on the bright side'. The appropriate answer is [D].