The correct answer is 10.86 moles.
It is a stoichiometry based problem,
One can solve this by just knowing the balanced chemical equation. The reaction where PbO2 is used and water is generated is:
Pb + PbO₂ + 2H₂SO₄ → 2PbSO₄ + 2H₂O
The mentioned reaction is witnessed in the lead storage battery.
Therefore, here as per the balanced equation one mole of PbO₂ is consumed providing two moles of water. So, for 5.43 moles of PbO₂, we will get,
2 × 5.43 moles of water = 10.86 moles.