The correct answer is D Fish ( someone asked me to explain why d is the answer) A sponge obviously doesn’t have a brain, a hydra is an organism and organisms don’t have brains ( hydra also doesn’t have eyes)
Vertebrata
Vertebrata is a group that contains various organisms which possess vertebrae (backbones). Animals that belong to the group are called vertebrates, and they include mammals, birds, fish, amphibians, and reptiles. The backbones in the animals extends from the head to the tail, and it encloses and protects the main nerve cord. The body of vertebrates is divided into trunk, and tail regions. They also possess a unique tube shaped brain, a distinct head, and three pairs of sense organs.
Answer:
Option B
Explanation:
The presence of these structures in this stage may be a prediction of a common ancestor as these structures are not gills because they do not develop into gills in chicks and humans but being so similar to gill structures in fish at this stage in their embryo suggests that chicks and humans share a common ancestor with fish.
Any theory can be disproven. A theory is simply a hypothesis that has been accepted as generally true, however in the realm of science, anything can be disproven.