According to the article, why did the Ice Bucket Challenge become so well-known?

Three new drug treatments for ALS were developed.
Three leaders with ALS worked very hard to spread the word.
People learned about ALS after Lou Gehrig had it.
Many patients with ALS were able to get better care.

The Ice Bucket Challenge became well-known because three leaders with ALS worked very hard to spread the word about the disease and raise awareness and funds for research.