问题如下：
Prudent valuation of all trading positions is an important revision to the Basel II market risk framework. Which of the following characteristics listed below not reflect prudent practice in this area?
选项：
A.the average volatility of the bid-ask spread.
B.the age of the positions.
C.the volatility and average trading volumes.
D.positions valued for liquidity level need to be marked-to-market only.
解释：
D is correct.
考点：revision to the Basel II market risk framework
解析:
在确定非流动性头寸的准确性时，要考虑以下几个因素，它们包括但不限于，市场集中度、买卖价差的平均波动率、交易量的波动率和均值、头寸持有时间以及对冲特定头寸风险所需要的时间。
选项D正确。
请教下老师，怎么看出来是考对非流动性估值？
