Since 2010,the Federal Funds Rate Has Been Well Below the Rate

Since 2010,the federal funds rate has been well below the rate suggested by the Taylor rule.A likely explanation for the discrepancy is that ________.

A) the Fed's dual mandate prevents a close reliance on the Taylor rule
B) policy makers decided that instability of the coefficients prevents the Taylor rule from having any role in policy decisions
C) in the past,adherence to the Taylor rule led to policy mistakes
D) all of the above
E) none of the above