পঞ্চম শ্রেণির ছাত্রছাত্রী শিক্ষা সফরে যাওয়ার জন্য ঠিক করেছে। কোথায় এবং কীভাবে যাবে, সেটা কীভাবে নির্ধারিত হবে?

Question:

Which of the following HTTP status codes indicates that the client request lacks valid authentication credentials for the requested resource?

Options:

    
• A) 400 Bad Request
    
• B) 401 Unauthorized
    
• C) 403 Forbidden
    
• D) 404 Not Found
  

Correct Answer: B) 401 Unauthorized

Explanation:

The HTTP 401 Unauthorized response status code indicates that the client request has not been completed because it lacks valid authentication credentials for the target resource. Although the HTTP standard uses the term "unauthorized", the semantics indicate that authentication is required.

Why the other options are incorrect:

    
• 400 Bad Request: The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing).
    
• 403 Forbidden: The server understands the request, but refuses to authorize it. Unlike 401, re-authenticating with the same credentials will make no difference; the client lacks permission to access the resource.
    
• 404 Not Found: The server cannot find the requested resource. This does not indicate an authentication issue.