Although the actual questions are missing from your ask, here's how you can tell.
If the study will be messed up (added bias) through interaction with the subjects the study should be observational. For example if a biologists wanted to study the eating habits of wild birds in the tropics, they would need to do an observational study. if they did a controlled experiment, the birds will change their eating habits based on human interaction, thus making the study invalid.
If the study requires specific measurements, close monitoring, or contact and interaction with the subjects the study should be a controlled experiment. For example, if a scientist wanted to test out a new drug, the health of patients would need to be closely monitored.
Answer:
Convergent evolution
Explanation:
Convergent evolution is a type of evolution of similar features and/or structures between organisms that are not phylogenetically related. This type of evolution is known to create analogous structures/organs that exhibit similar or the same functions but were not present in the last common ancestor of these taxa. An example of analogous structures (and therefore also of convergent evolution) are the wings of bats and of insects (e.g., butterflies). Conversely, divergent evolution is a type of evolution where species phylogenetically related, i.e., species that share a common ancestor, evolve and accumulate differences over time.
B.false
Respiratory bronchioles or terminal bronchioles are also part of the conducting zone.