when a relationship's degree is more than binary (ternary and 4-ary....) and there is more than one arraw then in literature it is interpreted in two ways.
Since C has arrow it is interpreted as
for every ABD there is atmost one C [ ABD C]
Since D has arrow it is interpreted as
for every ABC there is atmost one D [ABC D]
Since C, D have arrows, in this interpretation it is interpreted as AC and AD and BC, BD
Since there are two interpretations if you follow first interpretation then Answer is (A) and if you follow 2nd interpretation then it is (B).
Note: Marks are given for A and B