Marissa is walking along the beach and finds an unknown organism on the shore. It has bilateral symmetry, a nongelatinous, segmented body that is bigger than 0.5 mm, an exoskeleton, and jointed appendages. In which phylum can the organism be classified?

The organism can be classified in the phylum Arthropoda.

Explanation:

Arthropods are the organisms that has segmented body which mean they consist of three segments i. e. head, thorax and abdomen. They are bilateral symmetrical i. e. their body is divided into two equal parts. It consist of exoskeleton which provides protection and support to the organism's body. These organisms have jointed appendages which are attached to their body i. e. leg and arm.

the answer is:

carbon dioxide