Energy can not be created nor destroyed, leaving the only possible answer to be "b," when energy changes from one form to another.
1. The sizes of their necks vary
One of the oldest arguments in the history of psychology is the Nature vs Nurture debate. Each of these sides have good points that it's really hard to decide whether a person's development is predisposed in his DNA, or a majority of it is influenced by this life experiences and his environment.
