What are the minimum requirements to compile a program without errors?
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Identification Division. Program-ID. Program-name.
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Identification Division. Program-ID. Program-name. Environment Division.
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Identification Division. Program-ID. Program-name. Environment Division. Data Division.
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Identification Division. Program-ID. Program-name. Environment Division. Data Division. Procedure Division.
The absolute minimum requirement to compile a COBOL program without syntax errors is the Identification Division with PROGRAM-ID and a program name. The Environment Division, Data Division, and Procedure Division can technically be empty or omitted for compilation (though the program won't do anything useful without them). The compiler needs to identify what it's compiling.
Per the COBOL language standard, the only division that is strictly mandatory for a program to compile is the IDENTIFICATION DIVISION with a PROGRAM-ID clause — it's what names the program. The ENVIRONMENT, DATA, and PROCEDURE divisions are all technically optional at the language-syntax level, even though real programs almost always need a PROCEDURE DIVISION to do anything useful.