Which row gives the correct description of one property of barium and one property of barium oxide?
- Aobservation: a few gas bubbles form on the metal surface; pH: $8$
- Bobservation: a few gas bubbles form on the metal surface; pH: $13$
- Cobservation: rapid effervescence is seen; pH: $8$
- Dobservation: rapid effervescence is seen; pH: $13$