Final Answer:
When the trade settlement record of the delivering party and the receiving party do not agree, the trade is DK'd (Don't Know). Option A is the answer.
Step-by-step explanation:
In financial trading, a DK (Don't Know) occurs when there is a discrepancy or disagreement between the trade settlement records of the delivering party (seller) and the receiving party (buyer). This discrepancy could be due to various reasons such as errors in trade details, miscommunication, or other issues. The term "DK" is used to indicate that one party does not agree with the details of the trade as recorded by the other.
The DK process initiates an investigation to reconcile the differences and resolve the discrepancy between the two parties involved in the trade.
Option A is the answer.