When was namaz Eid al-Fitr made obligatory?

a) 1 Hijri

b) 2 Hijri

c) 3 Hijri

d) 4 Hijri

Namaz Eid al-Fitr was made obligatory or compulsory in 2 Hijri. Eid al-Fitr is observed on 1st of Shawal after observance of a month of Fasting during Ramzan.