Sometimes at a child's birthday party someone will rub a balloon on another's head and stick the balloon to the wall. this works because
a. the wall and balloon have the same charge.
b. the balloon has less weight because it has become charged.
c. the balloon discharges current into the wall and the wall becomes charged just like the balloon was.
d. the wall and the balloon have opposite charges and this creates an attractive force between the wall and the balloon.