Sam creates a file named File1. When he uses the cat file1 command, he cannot retrieve the file. The message that appears on the computer screen is "File Not Found". Which of the following is the reason of the error message?
a. The file "File1" does not actually exist in the current directory.
b. The file "File1" is located in a different directory than the one currently being accessed.
c. There is a typo in the command 'cat file1' and it should be 'cat File1' instead.
d. The file "File1" does exist but it is empty, so there is no content to retrieve.