- 2 Years 2 Months 01 Day
- 2 years 3 Months 01 Day
- 3 Years 2 Months
- None of these
- b
-
Abu Bakkar Saddique (R.A) was first Caliph of Islam.
Usman Ghani (R.A) Caliphate tenure was longest tenure among all four Caliph.
