The right answer is the lobed body.
The name trilobite comes from the subdivision of the body into three longitudinal lobes:
A medial lobe, the rachis,
And two lateral lobes, the pleura.
There is also a subdivision into three regions from front to back: the cephalon ("head"), the thorax and the pygidium ("tail").
Ans.
Trilobite is an arthropod, that belongs class Trilobita. This class includes a group of extinct marine arachnomorphs. The characteristic represented by trilobites, throughout the life is presence of a three-lobed body.
As their name suggest, trilobites had three longitudinal lobes, named as a central axial lobe, and two flanked lobes or pleural lobes.
Thus, the correct answer is option) b). '3-lobed body.'
