Open circulatory system is present in
a)	Arthropods and mammals	b)	Mollusca and aves
c)	Arthropods and Mollusca	d)	Mammals and aves

(c)

Circulatory patterns are two types

Open Circulatory Pathways

Present in arthropods and molluscs in which the blood pumped by the heart passes through the large vessels into the open spaces of body cavity called sinuses

Closed Circulatory Pathways

Annelids and chordates have closed circulatory system in which the blood pumped by the heart is always circulated through a closed network of blood vessels. This pattern is considered to be more advantageous as the flow of fluid can be more precisely regulated