Step 1: Background.
Imperial Bank of India was converted into the State Bank of India (SBI) in 1955.
Step 2: Reasons.
The Imperial Bank ignored agricultural finance, misused authorities, and had a defective branch expansion policy, limiting rural banking.
Step 3: Analyzing options.
(A) Ignorance of agricultural business – True, Imperial Bank was urban focused.
(B) Misuse of authorities – True, management issues existed.
(C) Defective branch policy – True, branches were not opened in rural areas.
(D) All of these – Correct, all were reasons.
Step 4: Conclusion.
Therefore, the Imperial Bank was converted into SBI due to all of these reasons.