In the context of Vedic history, consider the following statements:

1. The Yajurveda contains the folk tradition and represents the popular religion of the Vedic period.

2. The Brahmanas are commentaries on the Vedas and explain social and religious aspects of sacrificial rituals.

3. The Upanishads raised the Vedic religion at a philosophical level and discarded the material aspect of sacrifices.

4. The Aranyakas is a book of prayers and chants set to tune.

Which of the above statements is/are correct?