People exposed to radiation are more_______ to suffer from certain forms of cancer, which can be ______ but can’t be ______at present      [ ]

A. more likely; treated; cured                  

B. more probable; treated; cured     

C. more possible; cured; treated                

D. more likely; cured; treated

某企业生产某种产品，年固定成本为50000元，当原材料为批量采购时，可使单位产品成本比在原来每件48元的基础上降低产品产量的0.4%，产品售价在原来每件75元的基础上降低产品产量的0.7%，则该企业的最优产量为（）

A.4000件

B.4500件

C.5000件

D.5500件