It is given that,
causes and the solutions is coded as ## << ** ??..............(I)
but what causes it is coded as && ## // ]] ................(II)
the digital care solutions is coded as << $$ {{ **...........(III)
but the digital problem is coded as $$ xx << &&................(IV)
From I, III and IV, the == <<.
From I and III, solutions == **.
From I and II, causes == ##.
From II and IV, but == &&.
From III and IV, digital == $$.
From I, and == ??.
From II, what it == ]] //.
From III, care == {{.
From IV, problem == xx.
The code for 'the' is '<<' and the code for 'digital' is '$$'.