We can rewrite the statement in if-then form as follows; If a person passes a comprehensive exam, then that person can obtain a master's degree.
How to rewrite the statement
This format expresses the relationship between the two conditions. Passing the exam is a necessary condition for obtaining a master's degree. This means that it must be true for the outcome to be true.
However, if you wanted to emphasize the negative consequence of not passing the exam, you could rephrase it as: If a person does not pass a comprehensive exam, then that person cannot obtain a master's degree.