— Happy birthday!

— Thank you! It's the best present I________ for.[ ]

A. should have wished

B. must have wished

C. may have wished

D. could have wished

某工厂有两个生产车间和一个装配车间，两个生产车间分别生产A、B两种零件，装配车间的任务是把A、B两种零件组装成产品。两个生产车间每生产一个零件后都要分别把它们送到专配车间的货架F1、F2上。F1存放零件A，F2存放零件B，F1和F2的容量均可以存放10个零件。装配工人每次从货架上取一个零件A和一个零件B后组装成产品。请用P、V操作进行正确管理。