Which of the following statements about women scholars in the Vedic period is/are correct?

1. Gargi was a key female philosopher mentioned in the Brihadaranyaka Upanishad.
2. Maitreyi engaged in philosophical discussions with her husband Yajnavalkya in the Upanishads.
3. Women scholars were often excluded from formal sacrificial rituals.
4. Women could freely participate in all religious and educational activities during the Vedic period.