【名词&注释】
乳牙根尖周炎(periapical periodontitis primary teeth)、症状不明显(symptoms was not obvious)、牙龈上皮(gingival epithelium)、髓室底(pulp floor)
[单选题]发自髓室底(pulp floor)至根分叉处的管道是
A. 管间吻合 B. 根管侧支 C. 根尖分歧 D. 侧支根管 E. 副根管