Which statement about SQL is true?

A: Null values are displayed last in the ascending sequences.
B: Data values are displayed in descending order by default.
C: You cannot specify a column alias in an ORDER BY clause.
D: You cannot sort query results by a column that is not included in the SELECT list.
E: The results are sorted by the first column in the SELECT list, if the ORDER BY clause is not provided.

ANSWER: A

EXPLANATION: Answer A is correct because of null values are displayed last in the ascending sequences.

INCORRECT ANSWERS:

B: Data values are displayed in ASCENDING order by default.
C: It is possible to specify a column alias in an ORDER BY clause (but not in a GROUP BY clause).
D: You can sort query results by a column that is not included in the SELECT list.
E: The results will not be sorted at all, if the ORDER BY clause was not used in query.