Why is cholera still a problem even though the cause of the disease is understood? a. outbreaks are common in places that have low development and limited resources to combat the illness. b. no known cure exists for cholera. c. outbreaks were common prior to the 20th century, but have since become more sporadic, making it harder to fight the disease. d. treatment for cholera is complicated, and most people who get the disease will die despite treatment.