问题如下：
A characteristic of negotiable certificates of deposit is:
选项：
A.they are mostly available in small denominations.
B.they can be sold in the open market prior to maturity.
C.a penalty is imposed if the depositor withdraws funds prior to maturity.
解释：
B is correct.
A negotiable certificate of deposit (CD) allows any depositor (initial or subsequent) to sell the CD in the open market prior to maturity. A is incorrect because negotiable CDs are mostly available in large (not small) denominations. Large-denomination negotiable CDs are an important source of wholesale funds for banks, whereas small-denomination CDs are not. C is incorrect because a penalty is imposed if the depositor withdraws funds prior to maturity for non-negotiable (instead of negotiable) CDs.
答案中所提及的 small-denomination CDs指的是什么
