The first organism depicts a human (you). The second figure is that of a mollusk (squid), the third is of an annelid (leech and the last is of another annelid (Nereis).
The circulatory system in humans is the closed type. In squid, as in belongs to the evolved class Cephalopoda, it has a closed circulatory system. Nereis is an annelid and has a closed circulatory system. But leeches have an open circulatory system despite being annelids.