Step 1: Understanding the Concept
The question asks to identify the 'de facto' executive authority in a state government in India. It's important to distinguish between 'de jure' and 'de facto'.
De jure means "by law" or "in principle". This refers to the legal head of the government.
De facto means "in fact" or "in practice". This refers to the person who actually exercises the power.
Step 2: Analyzing the Roles in State Government
(A) Governor: The Governor is the constitutional head of the state executive. All executive actions of the state government are formally taken in the Governor's name. Thus, the Governor is the de jure head. However, the Governor acts on the aid and advice of the Council of Ministers.
(B) Chief Minister: The Chief Minister is the head of the Council of Ministers. It is the Chief Minister and their cabinet who make the actual policy decisions and run the administration. Therefore, the Chief Minister is the real or de facto executive authority.
(C) Chief Secretary: The Chief Secretary is the head of the civil services (bureaucracy) in the state and is the principal advisor to the Chief Minister, but they are not the executive authority.
(D) State Police Chief: The head of the state police force, part of the administrative machinery.
Step 3: Final Answer
The Chief Minister is the actual, or de facto, executive head of the State Government. Therefore, option (B) is the correct answer.