what is the benefit of Using an external file ?
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(1) Even though the main program does not contain any input or output statements, it can reference the record area of the file.
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(2) Each subprogram can control a single input or output function, such as OPEN or READ.
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(3) Each program has access to the file.
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(4) All the above
To answer this question, the user needs to have knowledge about the concept of using an external file.
Option A is incorrect because it does not fully explain the benefit of using an external file. While it is true that the main program can reference the record area of the file even if it does not have input or output statements, this is not the main benefit of using an external file.
Option B is incorrect because it is a specific benefit that applies only to subprograms. It does not explain the general benefit of using an external file.
Option C is incorrect because it is too general. It does not explain the specific benefit of using an external file.
Option D is the correct answer because it includes all the benefits of using an external file. These include the ability for the main program to access the record area of the file, the ability for subprograms to control specific input or output functions, and the fact that multiple programs can have access to the same file.
Therefore, the answer is: D. (4) All the above.
An external file in COBOL is shared across separately compiled programs: any program with access to it can reference its record area even without performing I/O itself, each subprogram can independently control a single I/O operation like OPEN or READ on it, and any authorized program in the run unit can access the file — so all of these benefits apply together.