a very clever answer indeed...

this is a conversation between a child and his mother....
son : mummy...i wanted to be a vegetarian starting from this day onwards!
mum : y?
son : because, if i eat too much of all the cow's and goat's meat, there will be no way for them to give me their milk to drink. but i think I'll eat pork instead...
mum : but y? isn't pork is also one type of meat? u can't be a vegetarian if u eat ANY meat!
son : well....pig did not contribute anything to the world....so, might as well i eat them.right mum??
mum : ??????