input: 
  from typing import List
  
  def get_all_countries() -> List[str]:
      """ Retrieve a list of all countries from a JSON file and return them as a list of strings.
      >>> get_all_countries()
      ['Afghanistan', 'Albania', 'Algeria', 'Andorra', 'Angola', 'Antigua and Barbuda', ...]
      """
  
output:     
      import json
      with open('countries.json', 'r') as file:
          data = json.load(file)
      return [country['name'] for country in data]
  