What is the output?

A table (t1) contains 1000 random integer values in the first column (col1). The random
values range from 1 to 1000.
You execute this query:
SELECT col1 FROM t1 WHERE col1< 100
UNION
SELECT col1 FROM t1 WHERE col1 BETWEEN 100 and 200
UNION ALL
SELECT col1 FROM t1 WHERE col 1 >=900
What is the output?

A.
A list of unique values within the ranges of 1 -200 and 900-1000

B.
A list of unique values within the range of 1 -200 and a list of all values, including
duplicates, on the table within the range of 900-1000

C.
A list of all values , including duplicates, in the range of 1 -200 and a list of unique values
in the range of 900-1000

D.
A list of all values, including duplicates, in the ranges of 1 -200 and 900-1000

E.
An error, because mixing UNION and UNION ALL in the same query is not permitted