Step 1: Understanding the Concept:
Adam Smith, the author of "The Wealth of Nations" (1776), is the pioneer of classical economics and free-market ideology.
Step 2: Detailed Explanation:
- Statement A: Correct. This is the core of the "Invisible Hand" theory—unregulated competition leads to beneficial outcomes.
- Statement B: Incorrect. Smith was a proponent of "Laissez-faire" (non-intervention). He believed government should only handle defense, justice, and specific public works.
- Statement C: Correct. Smith identified the division of labor and labor productivity as the primary drivers of national wealth.
- Statement D: Correct. Modern economics uses Smith's foundations but incorporates Keynesian and other macro-interventionist policies for stability.
Step 3: Final Answer:
Statements A, C, and D are accurate descriptions of Smith's philosophy and its legacy. Statement B contradicts his free-market views.
Therefore, option (A) is correct.