Q.Metameric segmentation is the main feature of
a. Annelida
b. Echinodermata
c. Arthropoda
d. Coelenterata

Step 1. Metameric segmentation (metamerism) is the division of the body, both externally and internally, into a linear series of repeating units called segments, separated internally by septa.

Step 2. Annelida was the first phylum to evolve this feature — the phylum's very name (Latin annulus, a ring) reflects the ringed, segmented body, as seen in the earthworm and Nereis. …

Recall which phylum the chapter identifies as evolving true me …

• Choosing Arthropoda because its segments are more visually obvious, overlooking that Annelida is the phylum where segmentation is described as first appearing. …