【名词&注释】
有效性(effectiveness)、受益人(beneficiary)、可转让信用证(transferable letter of credit)、非现金结算(clearing of accounts)、流通性(negotiability)、中间商(middleman)、对开信用证(reciprocal letter of credit)
[单选题]以下信用证兑付方式中对受益人最有利的是:()
A. Sight payment L/C
B. Deferred payment L/C
C. Acceptance L/C
D. Revocable L/C