To answer this question, the user needs to know about HTTP status codes and their meanings.
HTTP status codes are three-digit numbers that represent the response status of a request made by a client to a server. The first digit of the status code defines the class of response, while the last two digits do not have any categorization role.
The status codes starting with 4xx represent an error in the request made by the client, while the status codes starting with 5xx indicate an error on the server side.
Therefore, the correct answer is:
The Answer is: C. Codes starting from 400