Þ C. EVERY QUERY IN A COMPOUND QUERY MUST RETURN THE SAME NUMBER O...

15. þ C. Every query in a compound query must return the same number of

columns.

ý A, B, D, and E. A is incorrect because the columns can have different names.

B is incorrect because the two columns are of the same data type group, which

is all that is required. It therefore follows that D and E are also incorrect.