a volcano in Hawaii erupting the construction of the Hoover Dam whalers of the 17th, 18th, and 19th centuries the Mississippi River flooding its banks each summer
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: Of the examples listed, which event is thought by scientists to have led to the greatest extinction?
Possibilities:
- a volcano in Hawaii erupting
- the construction of the Hoover Dam
- whalers of the 17th, 18th, and 19th centuries
- the Mississippi River flooding its banks each summer

whalers of the 17th, 18th, and 19th centuries