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:
| RESOURCE for organisms |  | RESOURCE TYPE | RESOURCE SOURCE |  | DIRECT OR INDIRECT? |  | ORGANISM CLASS |  |
| --- | --- | --- | --- | --- | --- | --- | --- | --- |
| sunlight | is | light energy | from the Sun | that is | directly | required by | plants | to survive |
| sunlight | is | light energy | from the Sun | that is | indirectly | required by | all living things | to survive |
| water | is | matter | available on Earth | that is | directly | required by | all living things | to survive |
| air | is | matter | available on Earth | that is | indirectly | required by | all living things | to survive |
| air | is | matter | available on Earth | that is | directly | required by | animals | to survive |
| air | is | matter | available on Earth | that is | directly | required by | plants | to survive |
| food | is | matter | created using water, air, and sunlight | that is | directly | required by | animals | to survive |
| food | is | chemical energy | created using water, air, and sunlight | that is | directly | required by | animals | to survive |
| habitat | is | an environment | on Earth | that is | directly | required by | animals | to survive |
Question:
Air is the matter available on Earth that is _______ required by plants to survive. Select the correct choice to answer the question or fill in the blank.
Choices:
(A) indirectly
(B) sometimes
(C) seldom
(D) directly
Answer:
(D) directly