What is the output of this program?

#!/bin/bash
demo_var=hello
readonly demo_var
demo_var=hi
echo $demo_var
exit 0

A. countw B. wcount C. wc D. count p E. None of the above

A. dm B. rm C. delete D. erase E. None of the above

A. rdir B. remove C. rd D. rmdir E. None of the above

A. x B. y C. a D. z E. None of the above