Plausible Explanations of the Lack of Positive Stock Market Response

Plausible explanations of the lack of positive stock market response for buyer announcements of bank acquisitions include:

A) Managers of the buyer's bank may not have as their principal goal the maximization of shareholder wealth. Managers may be interested in maximizing their own welfare.
B) Roll's hubris hypothesis which argues that managers overpay because they have excessive arrogance about their ability to produce profits from the merged organizations.
C) Bankers may be attempting to maximize shareholder value but the stock market may be focusing on the short run rather than the long run.
D) All of the above.