The chorion, amnion, and allantois are structures found in (choose the MOST inclusive taxon that applies)?

The chorion, amnion, and allantois are membranes that are characteristic of amniotes, which include reptiles, birds, and mammals. These structures play crucial roles in the development of embryos in a terrestrial environment by providing protection, gas exchange, and waste storage.

All reptiles possess these structures, making the option of all reptiles the most inclusive taxon specifically related to the presence of the chorion, amnion, and allantois. While these structures are also found in birds and mammals (which are descendents of reptiles), the question asks for the most inclusive taxon that applies broadly to the structures themselves, thus limiting it to reptiles.

The other options encompass broader groups but do not exclusively refer to those that possess all three of these extra-embryonic membranes. For example, while all chordates, tetrapods, and vertebrates include many organisms without these membranes, reptiles directly demonstrate the presence of these structures, highlighting why the first option is the correct choice.