Which of the following command line redirection characters instructs the shell to read from the current input source until a specific word, on a separate line and without and trailing spaces, is reach

The here-document operator << is followed by a delimiter token (e.g., EOF), and the shell feeds all subsequent lines as stdin to the command until it encounters that exact token on a line by itself with no leading or trailing spaces. This is a standard POSIX shell feature used to embed multi-line input directly in scripts without requiring a separate file.

<| is not a defined shell redirection operator in any POSIX or Bash specification.

!< is not a valid shell redirection character combination; ! is used for history expansion or negation in conditional contexts, not input redirection.

&<< is not a valid shell redirection operator; & is used with file descriptors for output duplication (e.g., 2>&1) but has no meaning combined with << in this way.