The correct option is 50 characters which is the widely accepted limit for the subject line in a Git commit message.

This limit keeps the one line subject concise so it fits cleanly in terminals and in the compact views of hosting tools. It prevents unwanted wrapping or truncation and leaves space for automatic prefixes that some workflows add.

Detailed context belongs in the body which is typically wrapped at a longer width. Keeping the short summary separate improves scanability in logs and pull request lists.

60 characters exceeds the conventional subject limit and is more likely to wrap or be cut off in common views.

72 characters is the common wrapping width for the commit message body rather than the subject so using it for the subject would be against the usual convention.

90 characters is far too long for a subject line in typical tools and is likely to be truncated or wrapped in narrow displays.

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