Concept: The Disaster Management Act, 2005 provides the legal and institutional framework for disaster management in India.
Step 1: Checking Assertion (A).
The Act provides for effective management of disasters. It creates authorities and responsibilities at national, state, and district levels.
\[
\text{Disaster Management Act, 2005} \Rightarrow \text{Institutional framework for disaster management}
\]
So Assertion (A) is correct.
Step 2: Checking Reason (R).
The Act ensures coordinated measures by different wings of government for prevention, mitigation, preparedness, response, and recovery.
\[
\text{Government coordination} \Rightarrow \text{Prevention + Mitigation + Response}
\]
So Reason (R) is also correct.
Step 3: Checking explanation.
Reason (R) explains why the Act provides effective management. It gives the mechanism through which disaster management becomes organised and coordinated.
Therefore, both Assertion and Reason are correct and Reason is the correct explanation.