Explanation:
Several types of exports can be executed when EXPORT runs in FULL mode. The types of exports that can be used are COMPLETE (not FULL!), CUMULATIVE, and INCREMENTAL, specifying by setting the INCTYPE parameter to COMPLETE, CUMULATIVE, or INCREMENTAL
Incorrect Answers:
1: This error related with value of INCTYPE parameter, not with tables identified for export. If you don't use the TABLE mode, EXPORT utility will export full database or all tables in the user schema.
2: User SYSTEM can perform exports, because it has EXP_FULL_DATABASE privilege as DBA user.
3: You can perform export without usage parameter FULL if you don't want to export full database.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 722-728
Chapter 15: Advanced Topics in Data Recovery

---