They did n't want to upset their friend 's parents .They felt guilty if they did n't ask permission .They wanted to be polite in another 's home .None of the above choices .
What may be the reason for them asking permission ?
I was at a friend 's house a few days ago and I was feeling thirsty . " Is it okay if I help myself to the juice ? " I asked , peering into the fridge . " Sure , " said my friend .