Answer choices: atom x is a liquid and atom y is a solid
atom y has one more proton than atom x
atomy has one more neutron than atom x
atom x is a metal and atom y is a non-metal.

The correct option is B) crystallization of molten material inside Earth.

Explanation:

Scientists often observe that when lava or volcano erupts certain useful minerals which were present inside the Earth also tend to flow with the lava. The crystallization of some molten material inside the earth might give rise to minerals of large crystalline shapes. When a volcano erupts, these crystals can flow along with the eruption. Such crystalline materials can be of utter importance and worth. Hence, option B is the correct option.