Concept:
India follows a federal system of government in which legislative powers are divided between the Union Government and the State Governments.
The Constitution clearly defines this distribution of powers.
Step 1: Examine Assertion A.
The Constitution distributes legislative powers between:
• Parliament
• State Legislatures
through the:
\[
\text{Union List, State List, and Concurrent List}
\]
mentioned in the Seventh Schedule of the Constitution.
Therefore, Assertion A is correct.
Step 2: Understand the three legislative lists.
• Union List -- Subjects on which only Parliament can make laws
• State List -- Subjects on which State Legislatures can make laws
• Concurrent List -- Subjects on which both Parliament and States can legislate
This division ensures proper functioning of the federal structure.
Step 3: Examine Reason R.
Reason R states that residual powers are vested in State Legislatures.
This statement is incorrect.
In India, residual powers belong to:
\[
\text{Parliament (Union Government)}
\]
and not the States.
Residual powers refer to subjects not mentioned in any of the three lists.
Step 4: Determine the relationship between A and R.
Since:
• Assertion A is correct
• Reason R is incorrect
the correct option is:
\[
\text{A is correct but R is not correct}
\]
Step 5: Conclusion.
Therefore, the correct answer is:
\[
\boxed{\text{A is correct but R is not correct}}
\]