A lab observation notes that in a grasshopper, hemolymph leaves vessels and bathes organs in body sinuses. The observation points to:

Most arthropods have an open circulatory system. Hemolymph is pumped by a heart into spaces of the hemocoel where it directly contacts tissues. This MCQ belongs to the Arthropoda topic in Animal Diversity-I and is written to test concept understanding rather than memorized wording.