dse 2009 question

[jane]

For Q.23, dse 2009, can anyone explain why the answer is option d i.e I,II,III are correct? shouldn't the correct option be (b), i.e I, II are correct?

[jane]

this is the link...http://economicsentrance.weebly.com/uploads/1/1/0/5/1105777/option-a-2009.pdf

[economist]

They are complements bacause increasing price of A reduces demand for B. Note that complements does not require min specification of utility. So they can be complements even if demand for good B becomes 0.

[jane]

got it... I was thinking in the lines of consumption of A and B... like consumption of A has gone up and that of B has fallen...