Balancing requires center of mass at pivot

Steps:

• The object balances on the pivot when the total center of mass (object + added weight) is directly above the pivot.
• The added weight near the left end shifts the total CM rightward to reach the pivot.
• Thus, the object's own CM must be right of the pivot to need left-side counterweight.
• Position D, right of the pivot, fits this requirement.

Why D is correct:

• By the principle of moments, equilibrium occurs when clockwise and anticlockwise torques balance; object's CM right of pivot creates clockwise torque countered by left weight's anticlockwise torque.

Why the others are wrong:

• A: Left of pivot would require right-side weight to balance, not left.
• B: At pivot would balance without added weight.
• C: Slightly right might not need as much left weight as shown.

Final answer: D