The correct option is D Rhodophyceae
Floridean starch is the storage polysaccharide present in the cells of red algae or rhodophyceae.
In green algae, starch in the form of amylose or amylopectin is the stotage form.
Brown algae stores sugar as laminarin.
Myxophyceae is blue green algae. It is a prokaryote. It has cyanophyceaen granules to store nutrients.