Concept:Use coordinate positions to determine the exact direction between two points.Explanation:Let east be +x and north be +y.Take A=(0,0).From Statement I:D is 4 km north of A, so D=(0,4).B is 5 km southeast of D, and triangle ADB is right angled at A.Thus AB=3 km east, so B=(3,0).C is 5 km south of B, so C=(3,−5).From C(3,−5) to A(0,0), the shift is 3 km west and 5 km north.So A is northwest of C.Statement I alone is sufficient.From Statement II:Let D=(0,0).E is 3 km west of D, so E=(−3,0).A is 6 km north of E, so A=(−3,6).B is 4 km south of D, so B=(0,−4).B is 5 km south of C, so C is 5 km north of B, giving C=(0,1).From C(0,1) to A(−3,6), the shift is 3 km west and 5 km north.So A is northwest of C.Statement II alone is also sufficient.
Answer:Data given in either statement I or statement II alone is sufficient to answer the question.Hence, the correct option is B.