Static electricity comes from...?

a)charges not in motion


b)electric current


c)like charges attracting


d)opposite charges repelling

Static electricity comes from...?
Lets do this by process of elimination. Opposite charges attract, not repel; so, it cannont be D. Like charges repel each other, so it cannot be C. Static electricity is defined as positive charges or negative charges being built up on an object by friction (say as rubbing your wool socks on a carpet). It is NOT electricity that flows as a current, so it cannot be B. So, A is what is left. If you've built up electrons from the carpet you've been rubbing your feet on to your socks - you now have a static negative charge. However, you touch a doorknob (acting as a conductor) and all those electrons leave your body and you get a good ol' shock.
Reply:Since "static" means 'at rest', it should be (a) charges not in motion.