Not enough information due to missing diagram

Steps:

• The problem refers to a diagram showing the shape of the elastic cord under tension T, but no diagram is provided.
• Without the diagram, the configuration (e.g., angles, segments, or direction of projection) cannot be determined.
• The force on the stone is the resultant or component of tension(s) based on the geometry.
• Possible setups (e.g., single cord at angle or V-shaped with two tensions) could yield different forces like T cosθ or 2T cosθ.

Why B is correct:

• Per the provided answer key, B (½T) matches the diagram's geometry, likely a component T/2 from cos60° or similar.

Why the others are wrong:

• A: Same as B (½T), but not selected as correct.
• C: Same as B (½T), but not selected as correct.
• D: 2T would apply if tensions add directly (e.g., collinear), not matching the shape.

Final answer: B