Which of the following organisms is an acoelomate? . earthworm . insect . flatworm . clam .

The correct answer is option C, Flatworm

Reason -

Acoelomate are group of organisms that do not have body cavity or coelem. They do not have a fluid filled cavity and have a triploblastic body plan.  

Since Flatfworms lacks the body cavity and so they are considered as Acoelomate. They are invertebrate organisms having unsegmented body and also possesses bilateral symmetry. They are parasite who live inside other animals and feed on their digested food. They possess a simple digestive tract, nervous system, and excretory system.

they dont have any evidence

the circled areas are referred to   as sunspots.   the sunspots are cooler than the   surrounding area.

sunspots are temporary phenomena on the photosphere of the sun that appear visibly as dark spots compared to surrounding regions. they correspond to concentrations of magnetic field flux that inhibit convection and result in reduced surface temperature compared to the surrounding photosphere.