Only the last one provides an actual evidence of having a common ancestor. The rest can be a result of living in a similar environments that makes life easier. For example, many species live next to water, as water provides more fertile ground for plants, and they might have similar behaviors (searching for water) but they might not be closely related.
so the correct answer is D.
I believe that it's an exhausted bear. Cellular respiration is the way plants and animals receive energy. If the bear is exhausted, it means it's cellular respiration is lacking.