据图所示，附墙支座受拉螺栓的螺母不得少于两个或应采用弹簧垫圈加单螺母，垫板尺寸应由设计确定，且不得小于（  ）。

A

100mm*100mm*100mm

B

100mm*100mm*10mm

C

90mm*90mm*10m0m

D

90mm*90mm*10m