Good question - Thought that I knew the answer, and was wrong. Now, I have a question. I ran the following against an existing database to prove/disprove the answer, and found the following:

SELECT COUNT_BIG(*) FROM test_table

98481

SELECT COUNT_BIG(testfield2) FROM test_table

98481

SELECT COUNT_BIG(ALL testfield2) FROM test_table

98481

SELECT COUNT_BIG(DISTINCT testfield2) FROM test_table

28452

Based upon testing, though brief, and the answer, I would assume that the correct answer is 1, 2, and 3. The answer description states that ALL is the default, whether used or not thus selection 1 would use the default of ALL as shown in the above example, correct?