The job is         to me because I have little experience, however, it is also        .[ ]

A. challenging; rewarding

B. challenged; rewarded

C. challenging; rewarded

D. challenged; rewarding

下列为含有B族维生素的辅酶，例外的是

A．磷酸吡哆醛

B．辅酶A

C．细胞色素b

D．四氢叶酸

E．硫胺素焦磷酸