The correct option for the question regarding opening an already existing sequential file in output (O) mode is B. deletion of the current content of the file. Detailed Explanation:

1. Understanding File Modes:
2. In programming, when you open a file, you specify a mode that determines how you will interact with that file. Common modes include:
   • Read (R): Open the file for reading. The file must exist.
   • Write (W): Open the file for writing. If the file already exists, it is truncated (emptied) to zero length.
   • Append (A): Open the file for writing, but new data is added to the end of the file without deleting existing content.
   • Output (O): This is often synonymous with the write mode, which means that if the file exists, its current content will be deleted.
3. What Happens in Output Mode:
4. When you open a file in output mode (often referred to as write mode), the operating system prepares the file for writing. If the file already contains data, that data is deleted immediately upon opening the file. This means that the file is effectively reset to an empty state, and any previous content is lost.
5. Why Option B is Correct:
6. Since output mode (O) leads to the deletion of the current content of the file, option B is the correct answer. This behavior is standard across many programming languages, including C, C++, and Python, where opening a file in write mode will clear its contents.

Why Other Options are Incorrect:

• Option A: Buffer Overflow:
• A buffer overflow is a programming error that occurs when data exceeds the storage capacity of the buffer. This is not directly related to opening a file in output mode. Instead, it is a concern during data manipulation and memory management, not file opening.
• Option C: Duplication of the Current Content of the File:
• This option is incorrect because opening a file in output mode does not duplicate its content; it deletes it. Duplication would imply that the existing data is copied somewhere, which is not the case when a file is opened in this mode.
• Option D: Addition of New Data to the Content of the File:
• This option is also incorrect. Opening a file in output mode does not add new data to the existing content; it clears the file first. If you want to add data without losing the existing content, you would use append mode (A).

Summary of Key Points:

• Opening a file in output mode (O) deletes the current content of the file.
• This behavior is standard across many programming languages.
• Other options (A, C, D) do not accurately describe the effects of opening a file in output mode.
• Always be cautious when using output mode to avoid unintentional data loss.

By understanding these concepts, you can better manage file operations in your programming tasks and avoid common pitfalls related to file handling.