Astalked, sessile marine organism has several feathery feeding structures surrounding an opening through which food enters. the organism could potentially be a cnidarian, a lophophorate, a tube-dwelling worm, a crustacean, or an echinoderm. which of the following traits, if found in this organism, would allow the greatest certainty of identification
a water vascular system
The right answer to this question is water vascular system.
Through this system it's possible to identify it easily an echinoderm, that's why we can use it as a method of checking the information. But be careful, because for example, the radial symmetry, is not present in all the kinds of animals said on the question, shrimps are good examples, shrimps are part of the crustaceans. In this way, as you first see the organism, you are going to guess what it is by its appearance, and then you're going to analyse it properly after. Once you check it has a water vascular system, it's most probably to be an echinoderm.