Most advanced invertebrates are

Cephalopods such as octopus, cuttlefish and squid (coleoids) are the most advanced invertebrates among the given options. They belong to class-Cephalopoda of phylum - Mollusca. These organisms have a prominent head and a set arms or tentacles. They are widely regarded as the most intelligent of invertebrates and have well-developed senses and larger brains. Their nervous system is the most complex of all invertebrates.