input: from typing import Any
  
  def list_all_countries(data_path: str) -> Any:
      """ Reads a json file from given path and returns a json response containing all countries.
      >>> list_all_countries('data.json') # Assume data.json contains a list of countries
      {"countries": ["United States", "Canada", "Mexico", "Brazil", "Argentina", ...]}
      """
output:     import json
      with open(data_path, 'r') as file:
          data = json.load(file)
      return {"countries": data}