Design an ER diagram for the Online Travel Booking System. The system consists of a travel agent who acts as an intermediate between customers and the bus transport service providers. Any user, before accessing the service from the travel agency, they must be registered with it. Once registered, the user can search for a bus as per his requirements such as date of travel, source and destination location. Based upon the user query, the travel agent requests all the bus transport providers and responds the user with the details such as date, source, destination, bus transport provider name, bus timings and bus fare. The user books the ticket by selecting any one of the details from the displayed list which satisfy his requirements. As the user books the ticket by providing necessary details, it must be entered at transport provider's database and also the travel agent database. Specify key attributes of each entity type. Make appropriate assumptions to make the specification complete. The report should contain the following lines B 1.1 Introduction and problem definition B 1.2 Identification of entities and attributes B 1.3 Identification of relationship and relationship types B 1.4 Draw ER diagram B 1.5 Conclusion