Walking across a carpet can build up a charge by?

A. Contact

B. Friction

C. Induction

The correct answer for above statement is:

Walking across a carpet can build up a charge due to friction.

Explanation:

As you walk, some electrons are peeled away and a potential difference can grow up. The covered floor is a nonconductor (or can be the surface that is stripping away the electrons) so the charge can’t evanesce from your body till you encounter a metal doorknob or something grounded.

Walking across a carpet can build up a charge due to friction