(c) might actually be thought to contain a tetracolon. To the three tightly constructed sequences of noun of relationship (fem.) + genitive in the initial three cola is added a fourth containing the same construction in reverse order; moreover, the term nabhih may be seen as signaling a relational status superior to those of the temporal world.
VIII.48.3ab is probably the best known responsive tetracolon in the Rigveda.
(b) is the most tightly constructed tetracolon in the Rigveda, a perfect parisyllabic responsion made up of elemental ritual shouts.
Nevertheless, the overall structural similarity of all four padas suggests rather a tetracolon.