What is true of all adult sponges?
Options:
- (A) they are immobile.
- (B) at or near the margins
- (C) They may not survive.
- (D) water conservation
- (E) Light passing through water
- (F) competition
- (G) To keep their body heat.
- (H) permineralization OK. Let's think hard:
Adult sponges are sessile. Sessile Attached permanently, immobile. Adult sponges are attached permanently, immobile.
So, the final answer is (A).