B, Rocks are always being recycled into different forms.
PH=-log[H⁺]
pH=-log(1.87×10⁻¹³)
pH=12.72
I hope this helps. Let me know if anything is unclear.
According to the topic on stars, galaxies and the universe, the characteristics that are used to classify stars are color, temperature, size, elemental or compound composition, and brightness. Among these factors give, the characteristic not used to classify stars is distance from the earth.