Explanation:
User Global Area (UGA) components may reside in the large pool in MTS configuration.
Incorrect Answers:

1: UGA stands for User Global Area, and it represents the amount of memory allocated in Oracle for a user session. So it may contain not only sort areas.
2: In dedicated configuration session information, such as private SQL area, is stored in the memory allocated to the user process and it is called the PGA, or Program Global Area.
4: The UGA components may not reside in the buffer cache by definition.
Oracle 8, DBA Certification Exam Guide, Jason S. Couchman, p. 858-859. Chapter 18: Tuning Memory and Operating System Use

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