Solution

The correct answer is (C), (D), (B), (A).

Key Points

• Open the file: The first step in file handling is to open the file using the appropriate mode (read, write, etc.). This is done using functions like fopen() in C.
• Check for error: After attempting to open the file, it's crucial to check whether the file was successfully opened. This involves checking if the file pointer is NULL.
• Read from or write to the file: Once the file is successfully opened and error checking is done, you can perform read or write operations using functions like fread(), fwrite(), fprintf(), fscanf(), etc.
• Close the file: Finally, after all the necessary operations are done, the file should be closed using the fclose() function to free up resources.

Thus the correct answer is ​(C), (D), (B), (A).

Additional Information

• File handling is a crucial concept in programming that allows you to store and retrieve data from files. It is widely used for data persistence, configuration management, and logging.
• Proper error handling during file operations is essential to ensure data integrity and to handle exceptional conditions gracefully.
• Closing the file is important to free up system resources and to ensure that data is correctly written to the file, especially in buffered I/O operations.