While on a biological expedition, you discover a new species with the following characteristics: it has an exoskeleton, exhibits bilateral symmetry, and has jointed appendages. what phylum does this newly discovered organism belong to?

This is an incomplete question as it lacks the option which are:

Platyhelminthes

Mollusca

Porifera

Arthropoda

Nematoda

The correct answer will be option- Arthropods

Explanation:

A phylum is the taxonomic ranking of the Hierarchical system of classification which shares a set of features which can distinguish them from organisms of another phylum.

The Phylum Arthropoda is named so because it contains the animals with jointed legs. The animals possess hard exoskeleton and segmented bodies.  

Since the characteristics of the given species are similar to the characteristics of the arthropods like jointed legs on the basis of which the phylum is named therefore Arthropods is the correct answer.

you're crazy : )