Question: What was the most immediate and serious challenge faced by Hazrat Abu Bakr Siddiq (RA) immediately after becoming Caliph?
Correct Answer: A. Apostasy movement
Explanation: After the Prophet's ﷺ death, many Arab tribes rebelled, refused to pay Zakat, or claimed false prophethood. Abu Bakr (RA) launched the Ridda Wars to crush apostasy and reunite Arabia under Islam