Which of the following is a common code smell?

• A. Excessive comments.
• B. Very small classes always.
• C. Perfectly modularized code.
• D. Long methods.

Answer: (D)

Code smells are patterns in code that hint at deeper problems and potential maintenance pain. Long methods are a common smell because they force readers to hold lots of details in working memory, making the code hard to follow and reason about. When a single method stretches for dozens or hundreds of lines, it often means it’s trying to do too many things at once or contains nested logic that would be clearer if split into smaller pieces. The usual remedy is to extract smaller, well-named methods that each handle a single task, and to consider refactoring the surrounding structure if responsibilities are spreading too thin. This improves readability, makes testing easier, and supports reuse.

Excessive comments can indicate unclear code, but they aren’t as reliable a signal as a particularly long method. Very small classes aren’t inherently bad; they can be perfectly reasonable if they have clear, focused responsibilities. Perfectly modularized code isn’t a smell at all; it’s typically a sign of good design.