The Correct answer is Option 3. Explanation & Key Takeaways: The passage explains that in certain situations, excess brain drain can benefit both the sending and receiving countries. • Statement (a) is correct because the passage clearly mentions that migration brings valuable foreign exchange to the sending country. • Statement (b) is correct as the migration of surplus trained manpower helps reduce unemployment in the native country where job opportunities are limited. • Statement (c) is also correct because, at the global level, such migration helps increase the tempo of economic development, benefiting the sending country indirectly. • Statement (d) is incorrect since the passage does not mention population reduction as a benefit of excess brain drain. Therefore, the correct answer is Option 3: Only a, b and c.