The two largest religious groups are those following the Abrahamic traditions (sects such as Jews, Christians and Moslems) and the those following the Dravidian traditions (sects like Hindus, Buddhists, etc)
The largest population country is Indonesia.
The answer depends on what you discussed in class! Alaska is the largest US State. Texas is the largest state in the "lower 48". Beyond that you may wish to consult your class notes.
Islam is a religion that can be represented by Islamic Community, Islamic state, Islamic nation, or Islamic world.
Indonesia
Islamic
United of Arab Emirates
Indonesia
TASMANIA
Kazakhstan
Arabic
The largest Islamic countries by area are (1) Algeria, (2) Kazakhstan, (3) Saudi Arabia, (4) Sudan, and (5) Iran.