Which of the following commands will NOT update the modify timestamp on the file /tmp/myfile.txt?

The `file` command is used for identifying file types and only reads the file's content and metadata without making any modifications. Therefore, executing `file /tmp/myfile.txt` will not update the modification timestamp of the file.

Redirecting output with `echo "Hello" >/tmp/myfile.txt` truncates and writes new content to the file, which is a modification and updates the modification timestamp.

The `sed -ie "s/1/2/" /tmp/myfile.txt` command with the `-i` option modifies the file in place, changing its content and consequently updating its modification timestamp.

Appending output with `echo -n "Hello" >>/tmp/myfile.txt` modifies the file by adding content, which updates its modification timestamp.

The `touch /tmp/myfile.txt` command's primary function is to update the access and/or modification timestamps of a file to the current time.