The SORT verb in COBOL allows you to specify one or more keys from the record as sorting criteria. These keys determine the order in which the records are sorted.

In Object-Oriented COBOL, the process of creating a new object from a class is known as "INSTANTIATION." It involves creating an instance of a class with its own set of data and behavior.

The OPEN verb in COBOL is used to establish a connection between a COBOL program and an external file. It prepares the file for subsequent READ or WRITE operations.

A nested array in COBOL is created when the OCCURS clause is used within another OCCURS clause. This allows for the creation of more complex data structures, such as tables of tables or matrices.

For creating a new file and writing data to it, the correct file access mode is OUTPUT. This mode is used to write records to a file and create a new file if it does not exist. It does not allow reading or updating existing records.

The REDEFINES clause in COBOL is used to separate the storage of a group data item and another data item. It allows the same area of storage to be referenced using different data descriptions, providing versatility in data usage.

The data type PIC S9(5)V9(2) COMP-3 in COBOL is used to represent fixed-point decimal numbers. The COMP-3, or packed decimal, format is suitable for efficient storage of decimal data, with each digit represented by half a byte.

The GROUP clause in COBOL is used to declare a variable as a subordinate item of another variable. It helps in organizing related data items under a common name, making the structure of the data more readable and manageable.

To access a specific element within a table in COBOL, you typically use an INDEX variable. The INDEX variable represents the position of the element within the table and is used to navigate and retrieve data from the array.

In COBOL debugging, a "core dump" refers to a snapshot of the program's memory contents at a specific point in time. It helps developers analyze the state of the program's variables and memory structures, aiding in identifying the cause of issues.

"INPUT" is the file access mode used in COBOL when you only need to read records from a file. This mode allows the program to read data from the specified file but does not allow writing or updating records.

Polymorphism in Object-Oriented COBOL allows a class to provide different implementations of a method based on the specific object type. It enhances flexibility by enabling a single method name to have different behaviors in different classes.