Please read the following table in Markdown format and then answer the question according to the table. Table cells in one row are seperated by '|', and different rows are seperated by '
'.

Table:
| Substance | States usually found in nature |
| --- | --- |
| water | liquid, solid, gas |
| rock | solid |
| metal | liquid, solid |
| glass | solid |
Question:
Which of the following materials is found mostly as a solid in nature? Select the correct choice to answer the question or fill in the blank.
Choices:
(A) Rock
(B) Metal
(C) Oxygen
(D) Water
Answer:
(A) Rock