The plant body having holdfast, stipe, and frond is characteristic of Laminaria.
Laminaria is a type of brown algae (a member of the class Phaeophyceae). It has a well-developed structure consisting of:
Holdfast: Anchors the plant to rocks or the sea floor.
Stipe: The stem-like structure that supports the fronds.
Fronds: The leaf-like structures that are responsible for photosynthesis.
Other options:
Thus, the correct answer is (A) : Laminaria.