27. In the United States, the M1 velocity of money (A) Was unpredictable until the late 1970s but then became more predictable. (B) Was predictable until the late 1970s but then became unpredictable. (C) Was unpredictable until the late 19905 but then became more predictable. (D) Was predictable until the late 19905 but then became more unpredictable