The period of reign of Abū Isḥāq Muḥammad ibn Hārūn al-Rashīd is from___________?

The period of reign of Abū Isḥāq Muḥammad ibn Hārūn al-Rashīd is from___________?

A. 833-842
B. 750-850
C. 700-800
D. 687-792