Which group of organisms has the derived characteristics of true tissues, bilateral symmetry, and a pseudocoelom? sponges roundworms annelids chordates

pretty sure it is answer b

The correct answer is option B, Round worms

Reason -

Round worm belong to the Phylum Nematoda which has the following characteristics –  

1. They have a tissue system which has three layers –

a)Surfaces covering tissues

b)Internal tissues

c)Tissues forming the lining of the digestive system

2. They are bilaterally symmetrical

3. They have a complete digestive system with a distinct mouth and anus and thus are referred to as pseudocoelomates

oxygen = 21% of the atmosphere

nitrogen = 78%

carbon dioxide = 0.1%

argon =0.934%