A. the kelvin temperature scale
A first-hand source such as an experiment is called a primary source.
A primary source is where you can share new information or report on what you have discovered. Some primary sources are research data, interviews, audio recordings, and autobiographies.
A secondary source is where you describe and discuss about the primary sources. They are used to collect and gather primary source information. Some secondary sources are textbooks, review articles, and scholarly books.
A tertiary source is a source about summaries. A tertiary source can be used to look up information or get an overview about what it is you are wanting to know. Some tertiary sources are dictionaries, handbooks, encyclopedias, Wikipedia, and guidebooks.
The correct answer is B. unicellular.
Dinoflagellates are unicellular or multicellular, producers, and autotrophs, and apple trees are multicellular, producers, and autotrophs. All plants have numerous cells in them, so they can never be unicellular. The remaining characteristics they share with less complex organisms such as dinoflagellates.
