Billy was blowing up some balloons for his sister's birthday party. sally, his sister, grabbed a balloon and rubbed it on his head. billy's hair began to stick up in little spikes all over his head! then sally took the ballon and put it up against the wall. it stuck in place! "we learned about this in science class," sally said. billy's hair stood up and the balloon stuck to the wall because of
a) electromagnetism.
b) static electricity.
c) current electricity.
d) a magnetic force field.