Puzzle this time from Steven Feuerstein in Toad World

Hurry up, its an easy Puzzle this time from Steven Feuerstein in Toad World

Its May 2010, and this time Steven Feuerstein chose to play easy to his readers. I am reproducing the question and options here:

Which of the following choices correctly describe a feature of the Oracle database called "external tables"?

A. There is no such thing as an "external table" in Oracle; all tables are stored within the database.
B. External tables are tables defined in other databases, such as mySQL and SQL Server, which can be queried from within an Oracle database.
C. An external table is a read-only table defined in Oracle (it appears, for example, in the ALL_TABLES data dictionary view), whose data is stored in an operating system file.
D. An external table is a normal relational table that is accessed externally, usually from a Java method, and whose contents are displayed on web pages.

I am betting that all must know the answer:
Go to this webpage and click on the answer.

Best of luck to all of you.