SQL Command to Modify Existing Records in a Table

The correct answer is 'C. update'.

The UPDATE command is used to modify existing records in a table. Here's a breakdown of why the other options are incorrect:

• 'A. Insert': The INSERT command is used to add new records into a table.
• 'B. Select': The SELECT command is used to retrieve data from a table.

Example:

UPDATE Customers
SET ContactName = 'Alfred Schmidt'
WHERE CustomerID = 1;

This SQL statement would update the 'ContactName' field to 'Alfred Schmidt' for the customer with 'CustomerID' of 1.