Given below are two statements. One is labelled Assertion (A) and the other is labelled Reason (R).

Assertion (A): The central cavity of cnidarians is called the gastrovascular cavity.

Reason (R): It serves both digestive and circulatory functions. 

In light of the above statements, choose the correct answer from the options given below.

Assertion (A) is true. The gastrovascular cavity is a central cavity with a single opening in cnidarians.

Reason (R) is also true. The cavity allows for the digestion of food, and it also plays a role in the distribution of nutrients and gases throughout the organism.

(R) explains (A). The name gastrovascular cavity is based on its functions. The gastro part of the name refers to its digestive role, while the vascular part refers to its role in distributing nutrients and oxygen throughout the organism. Cnidarians lack separate circulatory and digestive systems, making the central cavity a crucial multi-functional organ. Digestion of food occurs in the gastrovascular cavity. Internal fluid currents within the cavity facilitate circulation.