What does "Which of the many" mean in the quote below?

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> During the past 35 years, opinions on unemployment have significantly influenced our thoughts about the process of economic development in low-income countries, the economic strategies appropriate for governments committed to accelerating that process, and the best way for the rich nations to assist in that endeavor. **Which of the many** and sometimes conflicting opinions of economists regarding the magnitude, causes, and costs of unemployment in LDCs reigns as the conventional wisdom at any given time is not determined by purely scientific criteria.
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> [Unemployment and Economic Development](https://www.jstor.org/stable/1153605)  
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> Albert Berry and R. H. Sabot,  
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> *Economic Development and Cultural Change*
> Vol. 33, No. 1 (Oct., 1984), pp. 99-116
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