[正答]
D
※国試ナビ4※ [100B018]←[国試_100]→[100B020]
[★]
B
※国試ナビ4※ [100B017]←[国試_100]→[100B019]
※国試ナビ4※ [100B019]←[国試_100]→[100B021]
.