1. Segmentation first evolved in the organisms of phylum Annelida, and vertebrates evolved more recently. How does the vertebrate body plan display segmentation and what are some associated benefits

Segmentation is a part of characteristic of the body plans of various goup of animals including the annelids, and recently developed vertebrates. There are three different segmental systems origin in development of the vertebrates that are - the somites, the rhombomeres and the pharyngeal arches.

benefits of the segmentation development are -

Different type of anatomical and morphological developments are helps in facilitate specific functions are led by the segmented body.

Paraxial mesoderm also have segmentation that helps in lateral movement

It also helps  in the consistent and fast interaction or communication in the neuronal system.

i think its both a and b