Replace the underlined word to correct the statement: Mahavira preached Jainism in Greek.

1. Prakrit.
2. Sanskrit.
3. Pali.

The Buddha gave his first sermon at:

1. Sarnath.
2. Takshila.
3. Bodhgaya.

The teaching of Mahavira was compiled into:

1. Puranas.
2. Tripitaka.
3. Angas.

If Buddha did not believe in the existence of God, then what was the central theme of Buddha's preaching?