Which of the following is NOT a pillar of Islam?

The correct answer is indeed C, as fasting during the month of Yom Kippur is not one of the pillars of Islam. Instead, Yom Kippur is a significant day of atonement in the Jewish faith, involving fasting and reflection.

In contrast, the pillars of Islam are foundational acts of worship and practice that define a Muslim's faith and actions. One of these pillars is the requirement to pray five times a day, which emphasizes the importance of establishing a direct connection with God throughout daily life. Another pillar is fasting during the month of Ramadan, which serves as a period of reflection, self-discipline, and spiritual growth. Additionally, charity to the less fortunate, known as Zakat, is crucial in Islam as it reinforces the community's responsibility to support those in need and emphasizes the importance of generosity and solidarity among members of the faith.

Therefore, C is the only choice that does not relate to Islamic teachings, highlighting its distinction from other options that are integral to the practice of Islam.