What output will the following command sequence produce? echo '1 2 3 4 5 6' | while read a b c; do echo result: $c $b $a; done

The `echo '1 2 3 4 5 6'` command pipes the string to the `while read a b c` loop. The `read` command assigns the first word ('1') to `a`, the second word ('2') to `b`, and all remaining words on the line ('3 4 5 6') to `c`. Consequently, `echo result: $c $b $a` outputs 'result: 3 4 5 6 2 1'.

This output would occur if `read` assigned the entire string to a single variable or if the variables were not reordered in the `echo` command.

This output is incorrect because variable `c` would contain '3 4 5 6', not just '3' or '4'.

This output implies a full reversal of the input words, which is not how `read` assigns multiple words to a limited number of variables.

This output is incorrect because `c` would contain '3 4 5 6', not just '3', and it misrepresents the full input assigned to variables.