Regular Catholics and even clergy were not to study scripture at all .  Only very old explanations  by  long dead saints were allowed . But Pius XII knew there was excellent work being done in that field by many Protestant scholars  and it was a bad idea to forbid persons who were catholic and willing to study SS to be discouraged  from doing so .
As far as I know probably Pius envisioned mostly or exclusively clergy to go into the study  involving ancient language , customs , et al   archeology,  etc.  
Had I known posting was for test credit might I have tried harder  ?  Dunno . I never studied theology because I felt I might end up in the looney bin  .  And I am not interested in all the discipline required for studies.   My hat's off to all you who are theologians  !