Adult sponges are sessile, and sessile Attached permanently, immobile. Given these facts, what is true of all adult sponges among the following options:
- they are immobile.
 - at or near the margins
 - They may not survive.
 - water conservation
 - Light passing through water
 - competition
 - To keep their body heat.
 - permineralization


 

 they are immobile.        