The statement is trying to create a table with columns of different data types and constraints. Here's what needs to be corrected:
* C: In Oracle, the LONG data type is used for character data of variable length up to 2 Gigabytes, but it is deprecated, and you should use CLOB or VARCHAR2 instead. Furthermore, a table cannot have more than one LONG column.
* D: The NOT NULL constraint should be specified at the column level, not at the table level. The correct syntax for creating a table with a NOT NULL constraint is to define it inline with the column definition, like this:
ename VARCHAR2(15) CONSTRAINT ename_nn NOT NULL,
The other options are incorrect:
* A: The foreign key constraint syntax is correct; the word CONSTRAINT is followed by the constraint name and then the REFERENCES clause.
* B: The foreign key constraint can be defined at the column level.
* E: While it's a good practice to name constraints, it is not mandatory for the primary key constraint to have a name; Oracle will generate one if it's not provided.
References:
* Oracle Documentation on CREATE TABLE: SQL Language Reference - CREATE TABLE
* Oracle Documentation on Data Types: SQL Language Reference - Data Types