Theories are a collection of scientific data that is generally accepted and reproducible. Theories are a result from several repeated experiments, but theories are not based on a single hypothesis. Several hypotheses are tested and appraised to become a well accepted theory. Theories may also be revised over time and can predict what may happen in the future. On the other hand, theories are not proven facts.
<span>The answer is : Both have true necks, while eusthenopteron has no neck. </span>We know that tiktaalik is more closely related to acanthostega than it is Ichthyostega eusthenopteron because Tiktaalik and Acanthostega both have true necks while eusthenopteron has none.
Plants need this waxy outer coating, also known as a cuticle, for a
variety of reasons. The cuticle keeps the important things the plant
needs in, such as water and carbon dioxide, and the things the plant
doesn't need, such as too much heat, out. It performs a few different
functions, including protecting the important cells needed for
photosynthesis.
I would guess C, hope that helps!