Explanation:

The question describes a database model characterized by the organization of data into linked tables. **Analysis of Options:** * **Option (A) Centralised database:** This term describes the physical architecture of a database, meaning all data is stored and managed at a single location. It does not define the logical structure or how tables within it are linked. A centralised database can indeed be relational, but 'centralised' itself does not explain the linking mechanism of tables. * **Option (B) Flat file database:** This type of database stores all data in a single table or file without explicit relationships between different data sets. It explicitly lacks the feature of 'tables linked by common field'; all data is typically contained within one large table. * **Option (C) Relational database:** Correct. A relational database organizes data into one or more tables (often called 'relations') of rows and columns. The defining characteristic of a relational database is that these tables are linked to each other through common fields (known as primary keys and foreign keys), establishing relationships between different sets of data. This perfectly matches the description provided in the question. * **Option (D) Null database:** This is not a recognized or standard type of database. 'Null' refers to the absence of a value in a database field, not a database architecture or model.