In COBOL programming, which guidelines should be followed to write a well structured, readable, and maintainable COBOL program?

Introduction / Context:
This question checks your understanding of structured programming practices in COBOL. Legacy COBOL code gained a reputation for being difficult to maintain mainly due to poor structure and heavy use of GO TO. Modern COBOL style emphasizes modular design, clarity, and predictable control flow. Interviewers want to know whether you can write COBOL that is easier to maintain and debug in large enterprise systems.

Given Data / Assumptions:

• We are writing production grade COBOL programs on mainframe systems.
• The goal is to improve readability, maintainability, and testability rather than to favor outdated habits.
• We assume the availability of structured constructs such as PERFORM, IF, and EVALUATE.
• The question focuses on good coding standards rather than any specific compiler option.

Concept / Approach:
Structured programming in COBOL promotes clear entry and exit points, modular code blocks, and minimal unstructured jumps. Using meaningful names, separating business logic into distinct paragraphs and sections, and designing from the top down helps reduce defects. The correct option should emphasize modularity, clarity, and limited use of GO TO. Distractor options will suggest poor practices, such as writing everything in one paragraph or avoiding comments.

Step-by-Step Solution:
Step 1: Identify which option mentions top down design, modular paragraphs, and meaningful identifiers. Step 2: Check whether that option also advises reducing GO TO statements and using structured control constructs like PERFORM and IF. Step 3: Review the other options to see if they conflict with widely accepted coding standards. Step 4: Recognize that long unstructured paragraphs, lack of comments, and obscure identifiers all make maintenance harder. Step 5: Select the option that aligns with standard COBOL coding guidelines taught in modern mainframe courses.

Verification / Alternative check:
A quick check is to ask whether the described practice would make code easier for a new developer to understand. Top down design, modularization, and meaningful names clearly improve readability. In contrast, a single long paragraph with heavy GO TO usage or code without comments is extremely difficult to maintain. Therefore, the only option that encourages structured, modular design must be correct.

Why Other Options Are Wrong:
Option b: Putting all logic in one paragraph with many GO TO statements creates so called spaghetti code that is hard to follow and very error prone.
Option c: Avoiding comments may reduce source file size slightly but greatly harms maintainability and onboarding of new team members.
Option d: Using only numeric field names does not help readability and is not a recommended practice in any COBOL standard or style guide.

Common Pitfalls:
Developers who learned COBOL many years ago may have inherited older, unstructured styles that rely on GO TO. Modern best practices strongly recommend structured constructs and clear modularization. Another pitfall is underestimating the value of comments and meaningful names, especially in systems that must be supported for decades. Remember that structured guidelines are not only academic; they directly impact maintenance cost and defect rates.

Final Answer:
Use top down design, modular paragraphs and sections, meaningful identifiers, and minimize GO TO statements by relying on structured control constructs.