Final answer:
Two different species with extensively identical chromosome banding patterns are most likely to be distant cousins, indicating they have a notable amount of DNA in common and a shared distant evolutionary history.
Step-by-step explanation:
If two different species have extensive identical chromosome banding patterns, they are likely to share a biological relationship that reflects their genetic similarities. These patterns suggest that the species have a considerable amount of DNA in common. Given the options provided, the correct answer is c) Distant cousins. This implies that the species are not closely related like parent-offspring or siblings, but they do share a connection that dates further back in their evolutionary history. Organisms of the same species generally have the highest level of DNA alignment and thus share characteristics and behaviors conducive to successful reproduction, which supports this idea.