What could be the reason for the following error?

View the Exhibit and examine the attributes of an undo tablespace.

In an OLTP system, the user SCOTT has started a query on a large table in the peak transactional hour that performs bulk inserts. The query runs for more than 15 minutes and then SCOTT receives the following error:

ORA-01555: snapshot too old

What could be the reason for this error?

A.
The query is unable to get a read-consistent image.

B.
There is not enough space in Flash Recovery Area.

C.
There is not enough free space in the flashback archive.

D.
The query is unable to place data blocks in undo tablespace.