A software team modifies a deployed application specifically to fix a bug reported by a customer, where the reports module produces incorrect totals under certain input conditions. Which type of software maintenance does this represent?

Corrective maintenance specifically refers to fixing discovered defects or bugs in a deployed system — exactly what is happening here, where an existing, reported error (incorrect totals) is being diagnosed and fixed. This differs from Adaptive maintenance (modifying software to work correctly in a changed environment, e.g., a new OS version), Perfective maintenance (adding new features or improving performance/usability beyond the original requirements), and Preventive maintenance (proactively modifying software to prevent future problems, e.g., refactoring for maintainability, before any failure has actually occurred).