People use many strategies for dealing with dialectical tensions. going back and forth between the two sides of a tension is a characteristic of which strategy?

Going back and forth between the two sides of a tension is a characteristic of alternation.

To add, in linguistics, an alternation is the phenomenon of a phoneme or morpheme exhibiting variation in its phonological realization. Each of the various realizations is called an alternant.

a is the answer because it just is