[单选题]Click the Exhibit button. Which statement is true

A The set variable contains all six elements from the coll collection， and the order is guaranteed to be preserved.

B The set variable contains only three elements from the coll collection， and the order is guaranteed to be preserved.

C The set variable contains all six elements from the coll collection， but the order is NOT guaranteed to be preserved.

D The set variable contains only three elements from the coll collection， but the order is NOT guaranteedto be preserved.