According to the author, The common explanation (first sentence in third paragraph) of connections between economic, military, and cultural development is _______.
A．revolutionary and too new to have been applied to the history of the Byzantine Empire
B．reasonable, but an antiquated theory of the nature of progress
C．not applicable to the Byzantine revival as a whole, but does perhaps accurately describe limited periods during the revival
D．essentially not helpful, because military, economic, and cultural advances are part of a single phenomenon