[正答]
B
※国試ナビ4※ [109I019]←[国試_109]→[109I021]
[★]
C
※国試ナビ4※ [109I018]←[国試_109]→[109I020]
※国試ナビ4※ [109I020]←[国試_109]→[109I022]
.