input: from typing import List
  
  def list_countries_api() -> str:
      """ Create a basic REST API using Python and Flask to list all the countries in the world. The API should read the list of countries from a JSON file named 'data.json' and return it as a JSON response when a GET request is made to the '/countries' endpoint.
      >>> result = list_countries_api()
      >>> result.startswith('import flask') and result.endswith("app.run()")
      True
      """
output:     import flask
      from flask import Flask, jsonify
      import json
  
      app = Flask(__name__)
  
      @app.route('/countries', methods=['GET'])
      def get_countries():
          with open('data.json', 'r') as file:
              countries = json.load(file)
          return jsonify(countries)
  
      if __name__ == '__main__':
          app.run()