I was born __________ five o'clock __________ the morning __________ October 10th.[ ]

A. in; on; at

B. at; in; on

C. at; on; of

将溶质质量分数为10%的盐酸5g加水稀释至250g，然后取出10g，则取出溶液中溶质的质量分数为[ ]

A、0.2%

B、0.5%

C、1%

D、2%