NO.PZ2024062801000078
问题如下：
Which of the following factors is least likely a contributor to the U.S. dollar shortage during the financial crisis?
选项：
A.
Banks’ prearranged credit commitments were drawn.
B.
Structured finance products became more difficult to sell.
C.
Central banks globally reduced their issuance of U.S. dollars.
D.
Banks brought off-balance vehicles back to their balance sheets.
解释：
C 美国以外的中央银行只能发行其本国货币。而只有美联储能够发行美元。导致美元短缺和银行越来越难以满足其美元债务责任的因素包括：难以出售流动性较低的结构性产品、将表外载体纳入银行的资产负债表，以及动用预先安排的信贷承诺。
请问d选项要怎么理解
