Question

identify the blue structure. pharynx auricle gastrovascular cavity lateral nerve cord

Explanation:

In many flat - worms, the pharynx is a muscular tube used for feeding and is often centrally located. The auricle is a sensory structure on the sides. The gastrovascular cavity is the main cavity for digestion and circulation. The lateral nerve cord is part of the nervous system. Based on typical flat - worm anatomy, the central structure is likely the pharynx.

Answer:

Pharynx