challenge: According to the 1989 US/USSR Joint Statement, what is a requirement for a ship to enter another state's territorial sea?
  
  A. The ship must be carrying a specific type of cargo
  B. Permission from the coastal state is always required
  C. The ship must adhere to the definition of innocent passage in Article 19 of UNCLOS
  D. The ship must fly the flag of the coastal state
  Answer: 