जोड्या जुळवून योग्य पर्याय निवडा :
व्यापार सिद्धांत | अर्थशास्त्रज्ञ
(a) निव्वळ खर्च लाभ | (i) पॉल क्रुगमन
(b) तुलनात्मक खर्च लाभ | (ii) हॅबर्लर
(c) संधी खर्च सिद्धांत | (iii) डेव्हीड रिकार्डो
(d) उद्योगांतर्गत व्यापार | (iv) अॅडम स्मिथ
पर्यायी उत्तरे :

The correct answer is Option D ((a)-(iv), (b)-(iii), (c)-(ii), (d)-(i)).

Key Points:
• Theories of International Trade & Their Proponents:
• Absolute Cost Advantage (a): Formulated by Adam Smith in *The Wealth of Nations* (1776), arguing trade occurs when countries possess absolute superiority in producing distinct commodities (iv).
• Comparative Cost Advantage (b): Introduced by David Ricardo in *Principles of Political Economy and Taxation* (1817), demonstrating trade gains exist even if one country has an absolute disadvantage in both goods (iii).
• Opportunity Cost Theory of International Trade (c): Advanced by Gottfried Haberler (1936), reconstructing comparative advantage without relying on the restrictive classical labour theory of value (ii).
• Intra-Industry Trade / New Trade Theory (d): Pioneered by Nobel laureate Paul Krugman (1979/1980), explaining two-way trade in similar differentiated products among industrialized nations with economies of scale (i).
• Correct code matching: (a)-(iv), (b)-(iii), (c)-(ii), (d)-(i) (Option 4).
• Key Takeaway: Trade theory pioneers: Absolute Advantage (Smith), Comparative Advantage (Ricardo), Opportunity Cost (Haberler), Intra-industry (Krugman).