I think answer is C.
What i think is when we use the word 'consider'means to Think about carefully or regrad as then we do not use 'consider as'.
'regard as' right but regard as being is not correct.

IMO C

Even in the following example the key to solving is the idiom related to consider, can anyone please clarify the rule for using consider please?

A special Japanese green tea called genmai-cha contains brown rice and is considered as a delicacy fit for a gourmet by most Japanese, though it is virtually unavailable outside Yokohama.

(A) A special Japanese green tea called genmai-cha contains brown rice and is considered as a delicacy fit for a gourmet by most Japanese, though it is virtually unavailable outside Yokohama.

(B) Considered to be a delicacy fit for a gourmet by most Japanese, genmai-cha is a special green tea that contains brown rice, virtually unavailable outside Yokohama.

(C) A special Japanese green tea called genmai-cha contains brown rice and is considered a gourmet delicacy by most Japanese, though it is virtually unavailable outside Yokohama.

(D) Most Japanese consider genmai-cha, a special green tea which contains brown rice, as a delicacy virtually unavailable outside Yokohama.

(E) Though virtually unavailable outside Yokohama, most Japanese consider genmai-cha, a special green tea that contains brown rice, a gourmet delicacy.

OA C

Can anyone post answer with correct explanation. IMO ans is B.

Why C and not A since

1)consider as
2) consider X Y

are all the correct idioms. Could anyone explain?