Sentence Correction (SC) | Re: Although all dogs are descended from the wolf and the jackal, the vari

I'll weigh in, but perhaps no one will be satisfied, as there is no definitive way to choose between A and B. Given a choice between "each other" and "one another," I'd probably go with "one another," since some people find this better for referring to relationships among multiple things (not just two). However, I have no indication that the GMAT relies on this as a rule. On the contrary, it's common to see SC questions that split between two interchangeable terms