Answer:
Economic requirements.
Explanation:
Due to economical reasons (making the bars affordable for the South Asian markets) they decided to adapt the form of the packs to suit their consumers. Hence, they were influenced by economic requirements.
It couldn't be legal requirements because no law forbids selling packs of bars in form of two or twenty.
No political requirement was mentioned in this hypotesis.
No new technology requirement would be necessary given that in Canada they sell them in packs of 10 or 20.
No cultural requirements is mentioned given that in the South Asian markets the bars are still being eaten - the only thing reduced is it's quantity which is explained by the economical reasons.