Final answer:
Open accounts leave sellers in a position where most of the problems of international commercial finance work to their disadvantage.
Step-by-step explanation:
Among the given options, open accounts leave sellers in a position where most of the problems of international commercial finance work to their disadvantage. An open account is a type of trade credit where the seller ships the goods or provides a service to the buyer without requiring immediate payment. In this case, the seller does not have any guarantee of receiving payment and is exposed to the risk of non-payment or delayed payment. This puts the seller at a disadvantage as they bear the risk of the transaction.
On the other hand, letters of credit, dollar drafts, forfaiting, and cash in advance provide some level of financial security and protection for the seller.