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
