Answer:
Due to its high intelligence.
Step-by-step explanation:
Scientists think that cuttlefish have the biggest brain to body ratio of all invertebrates that allows it to sense sight, smell, and sound that comes to it in the form of pressure waves. Due to this big brain, cuttlefish are very intelligent so due to its intelligence the scientists thinks that cuttlefish has the biggest brain as compared to other big vertebrates such as octopus.