Electrostatic attraction via induction on earthed conductor

Steps:

• Polythene rod, when rubbed, acquires charge (typically negative).
• Charged rod near earthed conducting water induces opposite charge on near side of water stream.
• Earth connection allows excess charge to flow, keeping water neutral overall but polarized.
• Polarization causes water to bend towards rod due to net attraction.

Why A is correct:

• Charged rod induces temporary charge separation in uncharged, earthed conductor, leading to attraction without net charge on water.

Why the others are wrong:

• B: Uncharged rod cannot induce charges or cause attraction in water.
• C: Uncharged rod cannot induce charges or cause attraction in water.
• D: Uncharged rod and uncharged water produce no electrostatic force for deflection.

Final answer: A