Which of the following types of SQL injection attacks extends the results returned by the original query, enabling attackers to run two or more statements if they have the same structure as the…

Error-based SQL injection manipulates database error-handling functions (such as EXTRACTVALUE or UPDATEXML in MySQL) to force the DBMS to embed query output inside error messages, extracting data through the application's error responses. Some certification materials broadly categorize techniques that retrieve additional data beyond the original query under error-based methods, though the precise definition in the question stem - same column structure, two statements, extended result set - aligns more accurately with UNION injection.

Boolean-based blind SQL injection sends conditional true/false payloads and infers data character by character from differing application responses, returning no direct result set extension.

Generic blind SQL injection returns no data in visible responses and relies on inference through timing delays or boolean logic rather than appending structured query results.

Union SQL injection (choice D is a corrupted or OCR-mangled rendering of 'Union SQL injection') is the technique that appends a UNION SELECT with matching column count and compatible types to extend the original query's result set - which precisely matches the question's description.