C since A would be dominant and if it was present the blood form could be A. If the blood kind is B which it's and heterozygous then it might be B and a further blood type akin to O. Edit: in writing it you wouldn't say BO tho. You might write it as Bb to exhibit that it is heterozygous. In case your instructor makes you write it like that most of the time then you would say option E so the anwser could truely be E in case your trainer doesnt need it to be certain.

B,C,D aka just C. The O is recessive so the A out masks it.

C

(B and D are also correct answers, but not complete)

c

C