Which command creates /home/labex/hard2 as a hard link to the existing /home/labex/hard1?
/home/labex/hard2
/home/labex/hard1
cp /home/labex/hard1 /home/labex/hard2
ln /home/labex/hard1 /home/labex/hard2
ln -s /home/labex/hard1 /home/labex/hard2
touch /home/labex/hard1 /home/labex/hard2