is a consistent relational database state in which every foreign key value also exists as a primary key value. a. Referential integrity b. First normal form (1NF) c. Database synchronization d. Function dependency

The correct answer is Option A (Referential integrity)

Explanation:

When a relational database table is in first normal form, that means it has no repeating fields or groups of fields, and hence all rows have the same columns, while if a relational database table is in second normal form, it implies that every non-key field is functionally dependent on the primary key. If can be in the third normal form if no non-key field is functionally dependent on any other non-key field.

A relational database on its own is a universal approved database model whose data is stored in tables divided into records and fields that serve as an information unit that organizes data points for easy access.

In the relational database, foreign keys are being checked to reference the primary key and enforce referential integrity so as to ensure that the foreign key must have a matching primary key. It means the reference from a row in one table to another table must be valid. Referential integrity concerns the concept of a foreign key normally enforced by the database management system.

given the options, i would say your best bet is c. the modem supports up to 56 kbps, which is too low for video streaming. dial up modems use actual phone lines, which only can go up to 56 kbps as that's more than sufficient for traditional phone calls. this is also the reason why when a dial-up modem connects, you hear all those sounds. it's literally using the phone line to establish a connection.