Most electronic devices of this kind, _______ manufactured for such purpose, are tightly packed.  [ ]

A. that are

B. as are

C. which is

D. it is

男，10岁，跌伤致左上臂近端酸痛1个月，无发热，X线示左肱骨近端有一椭圆形透亮区，中心位，骨皮质膨胀变薄，溶骨区呈单房状阴影，无骨膜反应

该患者最可能的诊断是（）。

A.化脓性关节炎

B.类风湿性关节炎

C.骨囊肿

D.骨纤维异常增殖症

E.骨软骨瘤