A rough draft is the preparation for a final essay and as I see it a rough draft may contain all of the elements mentioned in the given options. For example, prepositions, nouns and adverbs are also sure to be included, since it is a written piece and these are central components of any language. Transitions will probably be utilized, as you will probably build up a few points in your exposition and should change from thought to thought.
Answer: Ectotherms depend mainly on external heat sources, and their body temperature changes with the temperature of the environment. Animals exchange heat with their environment through radiation, conduction—sometimes aided by convection—and evaporation.