Answer:
d. no, because they are not multi cellular or eukaryotic.
Step-by-step explanation:
Blue-green algae are prokaryotic. They are basically Cyanobacteria. They can photosynthesise on their own. But all plants are Eukaryotas. Even though they can also photosynthesise like plants, they are unicellular.
Which means they lack certain eukaryotic cellular features. Thus, Plants in general are autotrophs but all autotrophs are not plants.