Well there are different types of Authority.
-the authority or power a person or a group has over another
- the authority to do something. (permission)
- an Authority over a particular subject. eg. your english teacher may be an Authority on Shakesphere, it means they know alot about something.
you have to talk about how authority is conveyed in each text and then relate them. For example I am reading 1984, the authority in this book is the authority Big Brother has over society, how to keep society under controll, they limit the language used to reduce individual thought, they introduce principles such as double think so that they can change history, in the end it gets to the extreme where despite any logic, 2+2=5 because that is what 'Big brother' leads them to believe.
Anyway getting back on trachk it really depends on which text you use and your understanding of it.
Hope I could help.