[正答]
C
※国試ナビ4※ [106I019]←[国試_106]→[106I021]
[★]
※国試ナビ4※ [106I020]←[国試_106]→[106I022]
※国試ナビ4※ [106I018]←[国試_106]→[106I020]
.