Step 1: Rule out Yashwant Sinha and Arun Jaitley, both later Finance Ministers unconnected to the 1991 reforms.
Step 2: Manmohan Singh executed the reforms as Finance Minister but is called the architect, not the "Father".
Step 3: As Prime Minister, P.V. Narasimha Rao gave the political authorisation for the 1991 liberalisation, earning him the title "Father of Indian Economic Reforms" - option (2) is correct.