A team of scientists is trying to classify a recently discovered species. The scientists decided first to determine whether its cells are prokaryotic or eukaryotic, and after close observation, determined that they were prokaryotic. What observation might have led to this conclusion?

Organelles, nucleus, no cell wall

Circular DNA found in the nucleus

Thick cell wall, DNA loose in cytoplasm

Organelles, nucleus, cell wall

Thick cell wall, DNA loose in cytoplasm.

The correct observation that might have led to the conclusion that the cells are prokaryotic is: "Thick cell wall, DNA loose in cytoplasm."