Sunken stomata can be traced in which of the following option(s)?

Xerophytes are plants grown in areas where there is less amount of water. Nerium sp., Pine, and Agave sp. are all examples of xerophytes.
Xerophytes have sunken stomata to prevent the loss of water. This is the characteristic feature of xerophytic plants.

Stomata are the tiny pores present in the green parts, predominantly in the leaves of the plants for gaseous exchange, not only gases but water also get lost through stomatal pores that lead to dryness of the tree.

Hence, option D is the correct answer.