Which caliph was assassinated by a Persian slave named Abu Lu’lu’a?

A. Ali ibn Abi Talib
B. Uthman ibn Affan
C. Umar ibn al-Khattab
D. Abu Bakr al-Siddiq

Answer: Umar ibn al-Khattab


Additional Information: Umar ibn al-Khattab, the second caliph of Islam, was assassinated by the Persian slave Abu Lu’lu’a while leading prayers.