Why did sanitation problems increase in industrial cities?

A. Overcrowding and poor housing के कारण / Because of overcrowding and poor housing

Step 1: Identify the concept: this is urbanisation problem. Step 2: Due to rapid migration housing and sanitation facilities were not enough. Step 3: Remember industrial city problems with overcrowding.

Step 1: concept पहचानें: यह urbanisation problem है। Step 2: Rapid migration के कारण housing and sanitation facilities पर्याप्त नहीं थीं। Step 3: Industrial city problems को overcrowding से याद रखें।