Answer:
Correct option is (a), Different copyright rules for pre and post 1978 works
Step-by-step explanation:
Copyright is a right given exclusively a person who has created a new work and reproduce it for a stipulated time. It is granted for a stipulated time period.
For all creations after 1978, copyright is granted for the years that the creator live and seventy years after his life.
For creations before 1978, that were not published, same rules are applicable as of post 1978 period. However, for works published before 1978, copyright was granted for total 95 years that is divided between 28 years from the date of registration of work and renewed for 67 years on expiry.
So copyright rules differ for works published pre and post 1978.