3. The "vertical" sets of 5 holes (in the video) are: a. "Shorted" together electrically by an underneath strip of metal, but are isolated (like an island) from all other holes. b. "Riveted" together electrically by an underneath strip of metal, but are isolated (like an island) from all other holes. c. "Shorted" together electrically by an underneath strip of metal, and are connected (like an island) to all other holes. d. "Shorted" together electrically by an underneath strip of metal, but are isolated (like a skunk) from all other animals