Answer :
To change the ownership of files and directories recursively within a directory, the appropriate options must be specified. In the context of command-line operations for the `chown` command, the recursive option is commonly used.
### Explanation:
1. --all: This is not a recognized option for recursively changing ownership with `chown`.
2. -a: This option does not exist for the `chown` command.
3. -R: The `-R` option stands for "recursive". It will change the ownership of the specified directory and all its contents, including subdirectories and files.
4. --recursive: This is another way to specify the recursive changing of ownership. It is a long-form version of the `-R` option and has the same effect.
### Conclusion:
The options that will change the ownership of files and directories recursively within a directory are:
- `-R`
- `--recursive`
Thus, the correct choices are:
C. `-R`
D. `--recursive`
### Explanation:
1. --all: This is not a recognized option for recursively changing ownership with `chown`.
2. -a: This option does not exist for the `chown` command.
3. -R: The `-R` option stands for "recursive". It will change the ownership of the specified directory and all its contents, including subdirectories and files.
4. --recursive: This is another way to specify the recursive changing of ownership. It is a long-form version of the `-R` option and has the same effect.
### Conclusion:
The options that will change the ownership of files and directories recursively within a directory are:
- `-R`
- `--recursive`
Thus, the correct choices are:
C. `-R`
D. `--recursive`
