The correct answer is (d), Lokpal.
An ombudsman is an independent official who is appointed to investigate and address complaints of maladministration or wrongdoing by public officials. The Indian model of ombudsman is called the Lokpal, which is a high-level anti-corruption body that was established in 2013. The Lokpal is responsible for investigating complaints against public officials, including ministers, judges, and members of parliament. It can also recommend disciplinary action or prosecution against those who are found guilty of wrongdoing.
The other options are incorrect. Lekhpal is a revenue official in India, Tehsildar is a revenue officer in charge of a tehsil, and Governor is the head of state of a state in India.