File accidently renamed

In uploading a file to my wordpress using filezilla, a file was accidently renamed and I didn’t see what it was originally! In the process of trying to backup the files on my computer, I accidentally hit the keyboard so now the file is called “b.”

The file is in the main folder as soon as I connect to the server. Could anyone tell me what this file SHOULD be named? I believe it was a “wp-… ” but I could be wrong.

Any help to fix my error would be greatly appreciated!

Thanks! ?? The file starts out like this…

<?php
/**
 * Handle Trackbacks and Pingbacks sent to WordPress
 *
 * @package WordPress
 */

if (empty($wp)) {
	require_once('./wp-load.php');
	wp( array( 'tb' => '1' ) );
}

/**

[Please post code snippets between backticks or use the code button.]