Final answer:
Alligators allegedly ended up in New York City sewers after flooding from a hurricane, but this is a widely believed myth with no concrete evidence to support it.
Step-by-step explanation:
The correct answer is C. Flooding from a hurricane. The myth of alligators in New York City sewers originated from rumors and urban legends in the 1930s. It was believed that alligators made their way into the sewers after being washed away during floods caused by hurricanes. However, there is no concrete evidence to support this claim, and it is widely considered to be a myth.