フリー問題

問題文

An administrator on a FreeBSD host needs a second name for a file so that the file survives even if the first name is removed. Which kind of link does that, and what boundary can that kind not cross?

選択肢

1. A second name that keeps the file alive after the first name is removed is a symbolic link and that kind of link cannot reach across a file system because the identifiers it relies on are only unique inside one of them.
2. A second name that keeps the file alive after the first name is removed is a hard link and that kind of link cannot reach across a file system because the identifiers it relies on are only unique inside one of them.
3. A second name that keeps the file alive after the first name is removed is a hard link and that kind of link cannot reach across a disk unit because the identifiers it relies on are only unique inside one of them.
4. A second name that keeps the file alive after the first name is removed is a symbolic link and that kind of link cannot reach across a disk unit because the identifiers it relies on are only unique inside one of them.