D) Transition

A database is a structured collection of data that is organized and stored in a way that allows efficient retrieval, modification, and management of the data. There are several types of databases, each with its own characteristics and uses. However, "Transition" is not a type of database.

Let's discuss the other options and understand why they are types of databases:

a) Hierarchical:
- In a hierarchical database, data is organized in a tree-like structure with parent-child relationships.
- It consists of a collection of records that are connected to each other through links.
- This type of database is suitable for representing one-to-many relationships.
- It is commonly used in mainframe environments.

b) Relational:
- A relational database is based on the relational model, which uses tables to store and organize data.
- Data is stored in rows and columns, and relationships between tables are established using primary and foreign keys.
- This type of database allows for efficient querying, data integrity, and flexibility.
- It is widely used in various applications, including business, finance, and e-commerce.

c) Network:
- A network database is similar to a hierarchical database but allows for more complex relationships between records.
- Instead of only one parent-child relationship, records can have multiple relationships with other records.
- This type of database is suitable for representing many-to-many relationships.
- It was popular in the past but has been largely replaced by relational databases.

Therefore, the correct answer is D) Transition. There is no such type of database called "Transition."