Let's analyze the given assertion and reason to determine the correct answer.

1. Assertion (A): Sustainable development is critical to the well-being of human society.
   • Sustainable development refers to meeting the needs of the present without compromising the ability of future generations to meet their own needs. It encompasses a balance between environmental, social, and economic factors.
   • This statement is true because sustainable development ensures that we utilize resources in a manner that supports long-term ecological balance, which is essential for the well-being of human society.
2. Reason (R): Environmentally sound policies do not harm the environment or deplete natural resources.
   • This statement is also true. Environmentally sound policies are designed to protect the environment and ensure sustainable use of resources, preventing depletion of these resources.
   • However, this reason focuses more on particular policies and does not explicitly address why sustainable development is critical to human well-being, thus not directly explaining the assertion.

Now, let's evaluate the options:

• Option 1: Both (A) and (R) are correct and (R) is the correct explanation of (A).
  • This is incorrect because although both statements are true, (R) is not the direct explanation of why sustainable development is critical.
• Option 2: Both (A) and (R) are correct, but (R) is not the correct explanation of (A).
  • This option is correct as it states that while both (A) and (R) are true statements, (R) does not directly explain (A).
• Option 3: (A) is true and (R) is false.
  • This is incorrect as both (A) and (R) are true.
• Option 4: (A) is false and (R) is true.
  • This is incorrect since (A) is true, not false.

Therefore, the correct answer is: Both (A) and (R) are correct, but (R) is not the correct explanation of (A).