单项选择题

A.宁夏枸杞>土枸杞>沣枸杞
B.宁夏枸杞>沣枸杞>土枸杞
C.土枸杞>沣枸杞>宁夏枸杞
D.沣枸杞>宁夏枸杞>土枸杞