This issue is best answered by these quotes:
'The general rule of ownership is stated in the Copyright Act as the following: "Subject to this Act, the author of a work shall be the first owner of the copyright therein."'(Canadian Copyright Law, 3rd ed., Lesley Ellen Harris, McGraw-Hill Ryerson Limited, 2001, page 81)
'The author and first owner of any paper, dissertation or other work prepared for school courses and degree programs is the author of the work, i.e., the student preparing the paper, dissertation, etc.'(Canadian Copyright Law, 3rd ed., Lesley Ellen Harris, McGraw-Hill Ryerson Limited, 2001, page 88)
'All "written" documents, whether prepared for internal or external purposes whether in draft of final form, whether in print or in digital form, are protected by copyright. In fact, each draft of a document may be separately protected by copyright. This includes papers and dissertations, and other school assignments prepared by students as part of course or degree work.' (Canadian Copyright Law, 3rd ed., Lesley Ellen Harris, McGraw-Hill Ryerson Limited, 2001, page 59)
For Graduate College purposes the final version of a thesis or dissertation will be the version that has formal approval as evidenced by the signatures of all members of the examining committee.