[正答]
C
※国試ナビ4※ [106I018]←[国試_106]→[106I020]
[★]
D
※国試ナビ4※ [106I017]←[国試_106]→[106I019]
※国試ナビ4※ [106I019]←[国試_106]→[106I021]
.