One of the Major Reasons Why the US Trade Deficit

One of the major reasons why the US trade deficit with China has grown in the last 10 years is that

A) the Yuan is seriously undervalued relative to where it would need to be to lead to a zero trade deficit.
B) the yuan is seriously overvalued relative to where it would need to be to lead to a zero trade deficit.
C) currency markets can never bring trade into balance,even in the long run.
D) US productivity has fallen recently.
E) the U.S.has suffered two sharp recessions.