Final answer:
Bacteria are prokaryotic and can be unicellular, while fungi are eukaryotic and can be either unicellular or multicellular.
Step-by-step explanation:
The answer to the question, "Both bacteria and fungi can be" is unicellular and multicellular. However, when it comes to cell type, bacteria are exclusively prokaryotic, while fungi are eukaryotic organisms. Bacteria fall under the domain of prokaryotes, which means they do not have a true nucleus, while fungi, like plants and animals, have eukaryotic cells with a true nucleus and other organelles. Some fungi, like yeasts, can be unicellular, while others, like mushrooms, are multicellular. Hence, the correct response options would be 'a' for multicellular and 'd' for unicellular, but it's important to recognize that only bacteria can be prokaryotic and not fungi.