Final answer:
When welding pieces of unequal thickness, it is important to point the electrode towards the thicker piece to maintain a shorter arc length and ensure a strong weld.
Step-by-step explanation:
When welding pieces that are of unequal thickness, it is important to point the electrode towards the thicker piece (option d). This is because a shorter arc length is desirable when welding thicker pieces, as it allows for better penetration and fusion between the two pieces. By pointing the electrode towards the thicker piece, the welder can maintain a shorter arc length and ensure a strong and effective weld.