单项选择题

根据以下信用证条款回答40-42题: Applicant:Peter Flowers Corp., Netherlands 231 Merry Street Amsterdam, Netherlands Beneficiary:May Flowers Corp., China 18 Chung Shan Road, Shanghai, China Documents required: Full set of clean on board ocean bills of lading made out to order and blank endorsed ,marked “freight prepaid”,notify applicant. 按提单收货人分类,该提单属于哪一种类?( )

A.记名提单
B.不记名提单
C.清洁提单
D.指示提单