(A) SQL
SQL (Structured Query Language) is a domain-specific language designed for managing data in DBMS. It is particularly useful in handling structured data.
CSV is a file format, Spreadsheet is an application, and TXT is a plain text file — none are languages for managing databases. SQL is the standard language used to query, insert, update, and delete data in relational databases. This is general computer science knowledge; the source passages focus on NLP, so recall this from your IT/CS fundamentals.