单项选择题

A.α-D-吡喃葡萄糖,β-D-吡喃葡萄糖,β-D-乙酰吡喃葡萄糖氨
B.β-D-吡喃葡萄糖,α-D-吡喃葡萄糖,β-D-乙酰吡喃半乳糖氨
C.β-D-吡喃葡萄糖,α-D-吡喃葡萄糖,β-D-乙酰吡喃葡萄糖氨
D.α-D-吡喃葡萄糖,β-D-吡喃葡萄糖,β-D-乙酰吡喃半乳糖氨