Answer:
sessile or relatively inactive.
Step-by-step explanation:
Sponges are the multicellular which contains channels and pores in their bodies to allow the movement of surrounding water in them. They belong to the kingdom Porifera and are one of the earliest forms of multicellular life on earth.
Since the sponges are one of the earliest forms of multicellular organisms on Earth, therefore, they do not move and remain attached to the underwater surface. Therefore they remain inactive and are sessile.
Thus, Option-B is the correct answer.