Answer:
C. The town had to be abandoned after clean-up efforts failed.
Explanation:
The land around Picher was surrounded by lead and zinc mining and the mine is said to be responsible for over fifty percent of the lead used to make bullets during the WW1.
The area became so toxic that residents were exposed to harmful toxins each time they stepped out of their homes and even though there were efforts to clean up the place, those efforts didn't work out.
Therefore, the final result of the toxic contamination of the land surrounding Picher, Oklahoma was that the town had to be abandoned after clean-up efforts failed.
