It draws a conclusion based on what would best explain one's observations.
Inference is the process where logical consequences evolve from premises that are assumed to be true. Knowledge backed with observations and reasoning as evidence is used to make conclusions. It is also referred to as an educated guess and is not necessarily factual.
The answer would be D. The definition of a homologous structure is an organ or body part that appears in different animals and is similar in structure and location, but doesn't necessarily share the same purpose. The birds and rabbits have similar bones in their forelimbs, but one uses them to run and other uses them to fly.
X-rays are the radiation that allows us to see through the skin to visualize bones
The answer would be A. the arrangement of DnA