Final answer:
To get a complete weather briefing for a planned flight, the pilot should request METAR reports, TAF forecasts, and PIREPs.
Step-by-step explanation:
To get a complete weather briefing for a planned flight, a pilot should request several types of reports and forecasts. METAR reports (option A) provide current weather conditions at a specific airport. TAF forecasts (option B) provide a detailed forecast for a specific airport. PIREPs (option C) are reports of actual weather conditions encountered by pilots in flight. Therefore, to get a comprehensive weather briefing, the pilot should request all of these types of information.