Ans.
Fern is a vascular plant that belongs to kingdom plantae, while flatworm is an animal that belongs to kingdom animalia. Both ferns and flatworms are eukaryotic organisms, having cells with membrane-bound organelles, such as mitochondria and nuclei.
However, chloroplast is only present in fern cells, while cells of flatworm lack chloroplast as it is found only in plant cells.
Thus, the correct answer is option). 'chloroplast.'
