Question

what is an organism is it a dna,nucleus,cytoplasm,or prokaryote

Answer 1

prokaryotes are single celled organisms

Answer 2

Prokaryotes are organisms.

Whereas DNA is the genetic information for organisms, found INSIDE the cells.
The Nucleus is what acts as a house for the DNA, also found INSIDE the cells.
The Cytoplasm is the region between the Nuclear Envelope and the Plasma Membrane, also found INSIDE the cells.
All these 'things' are found inside cells that make up some organisms.
Therefore, prokaryotes are the best answer.

If you did not know that Prokaryotes are organisms, process of elimination should help eliminate the other options.

Cheers!