A: Yes, one may make multiple intentions with one Nafl Qurbani and this may also include all deceased Muslims. However, if a person is able to afford separate animals for nafl (optional) Qurbani, then this is more meritorious.
And Allah Ta'ala Knows Best
Shafiq Jakhura (Mufti) M.D. Mangera (Mufti)
Fatwa Dept. Fatwa Dept.