Which sentence is unnecessary and could be eliminated without disturbing the flow and information of the paragraph? a) maybe there are other animals that have blue blood as well. b) lobsters are invertebrates with a hard protective exoskeleton. c) like most arthropods, lobsters must moult in order to grow, which leaves them vulnerable. d) lobsters, like snails and spiders, have blue blood due to the presence of haemocyanin which contains copper.