The correct answer is option 3: Khanqah. A Khanqah is a Sufi monastery or hospice where Sufi saints or sheikhs reside, teach spiritual practices, and guide their followers. It is a place for spiritual retreat, meditation, and communal worship. Khanqahs are significant in Sufism as they provide a space for Sufis to deepen their spiritual connection and seek guidance from the sheikh.

Option 1, Tripitaka, is not associated with Sufi saints. Tripitaka is the sacred scripture of Buddhism, comprising the teachings of Gautama Buddha.

Option 2, Dakhma, is not directly associated with Sufi saints. Dakhma is a Zoroastrian structure also known as a "Tower of Silence," where the dead are traditionally placed for exposure to the elements.

Option 4, Synagogue, is a place of worship for Jewish people and is not specifically associated with Sufi saints.

So, the correct answer is option 3: Khanqah.