Which of the following is NOT one of the Pillars of Faith of Islam?

The Pillars of Faith in Islam, also known as the Five Pillars, consist of essential acts of worship and practice that define a Muslim's belief and commitment. The pillars include the declaration of faith (Shahada), prayer (Salah), alms-giving (Zakah), fasting during Ramadan (Sawm), and pilgrimage to Mecca (Hajj).

Membership in a school of law, or al-madhahib, is not part of the foundational acts that all Muslims are required to observe. While schools of thought within Islamic jurisprudence provide important guidance on interpreting and practicing faith, being a member of a specific school of law is more about understanding and applying religious principles rather than an obligatory pillar that forms the core of Islamic faith and practice. Thus, recognizing the differences between the obligatory pillars and methods of legal interpretation clarifies why this choice stands apart from the essential acts of Islam.