Correct Answer:
B. 14 AH
The Battle of Qadisiyyah was a decisive battle fought between the Rashidun Caliphate and the Sasanian (Persian) Empire during the caliphate of Hazrat Umar (RA). The Muslim army, led by Sa'd ibn Abi Waqqas (RA), defeated the Persian forces under Rostam Farrokhzad.
The battle is generally accepted to have taken place in 14 AH (636 CE), although some historical sources mention 15 AH due to differences in the Islamic calendar and historical chronology.
The victory at Qadisiyyah paved the way for the Muslim conquest of Persia and marked the beginning of the decline of the Sasanian Empire.
Correct Answer: 14 AH