PLEASE HELP Which statement correctly identifies Old Faithful and explains how it formed?

It is a caldera formed from a vent collapsing.
It is a mud pot formed from pools of boiling, acidic mud.
It is a volcanic neck that formed as a result of magma that never erupted.
It is a geyser that formed due to water heated by magma erupting at Earth’s surface.

Aboy with an extra x chromosome probably has which of the following syndromes?

How do water’s relative densities as a solid and a liquid differ from that of most other substances? water’s solid and liquid forms have different densities, while most other substances have solid and liquid forms with similar densities. water’s solid and liquid forms have similar densities, while most other substances have solid and liquid forms with different densities. water’s liquid form is less dense than its solid form, while the opposite is true of most other substances. water’s solid form is less dense than its liquid form, while the opposite is true of most other substances.

What does the number 18.9984 represent in the image?