Which answer to accept is entirely up to the person asking the question.
Generally, one should as the asker accept the answer that was most helpful to oneself in solving the problem at hand. Note that this does not mean accepting the most upvoted answer. Compare what I wrote in response to a previous MWB question, Picking the sole answer as the best answer. A highly upvoted answer is usually a good candidate for acceptance, but that is not a prerequisite. (As a case in point, I recently saw an answer on The Workplace that had been downvoted to oblivion, yet was accepted by the OP.)
We are by design a speculative site; very few questions being asked here have hard-and-fast answers. Some questions seek answers drawing on various fields of science, whereas other questions do not need or want answers to be bound by the known sciences. That is something each person writing an answer to any question should respect.
Answers should obviously strive to explain why and how they answer the question as asked, and should ideally be clear about what they are proposing, but I feel that the bottom line is that we cannot, as a community, realistically impose a particular style on answerers. What each member of the community can do is to take how well the answer actually answers the question, as well as the answer's level of clarity, into account when deciding if and how to vote on the particular answer.