问题如下：
Bank holding companies(BHCs)' smoothing functions are very important. To protect the smoothing functions of BHCs, the Federal Reserve's Capital Plan Rule has set several requirments for BHCs. Accoring to these requirements, BHCs should hold an effective process for assesing capital adequacy for:
选项：
A.BHCs, U.S. only.
B.BHCs with more than 7 years of operational history.
C.BHCs with a net annual income of more than $5 billion.
D.BHCs with total consolidated assets of $50 billion or greater.
解释：
D is correct.
考点：the requirements under the Capital Plan Rule
解析：The Federal Reserve's Capital Plan Rule 要求 总资产大于等于500亿美元的BHC，要有有效的流程来监控、评估其自身的资本充足率。
这个BHC是什么意思
