Of all the vast tides of migration that have swept through history, maybe none is more concentrated as the wave that brought 12 million immigrants onto American shores in little more than three decades.

• Amaybe none is more concentrated as  
• Bit may be that none is more concentrated as  
• Cperhaps it is none that is more concentrated than  
• Dmaybe it is none that was more concentrated than  
• Eperhaps none was more concentrated than