[正答]
B
※国試ナビ4※ [105I019]←[国試_105]→[105I021]
[★]
A
※国試ナビ4※ [105I020]←[国試_105]→[105I022]
※国試ナビ4※ [105I018]←[国試_105]→[105I020]
.