Which of the following characteristic distinguish arthropoda from annelids and molluscs?

An arthropod has a segmented body covered by an exoskeleton made from chitin and other chemicals. 

This exoskeleton serves as protection and provides places for muscle attachment. 

Arthropods must moult because their exoskeletons do not grow with them. 

The body feature from which the phylum takes its name is the jointed appendages, which include antennae and mouthparts as well as walking legs.