A documentary credit expires in the country of the beneficiary and the advising bank. The advising bank is named as the nominated bank, and the amount of the documentary credit is available to the beneficiary against presentation of drafts drawn on the issuing bank at 30 days after shipment accompanied by specified documents in field 46
A: Of what type of availability is this a description?
选项：

A: Acceptance.
B: Deferred payment.
C: Negotiation.
D: Payment.