What is the minimum obligatory portion of Quranic recitation required to validate the pillar of Qira'ah?

The Pillars of Prayer (أركان الصلاة) Part 1: Standing and Recitation

• The entire Surah al-Fatihah.
• One complete long verse or three short verses.
• Exactly one word, like "Nun".
• Half of any Surah.