Concept:Rubbing two different materials transfers electrons, producing opposite charges by friction.
Explanation:When two different materials are rubbed together, their surfaces come into close contact.
One material has a greater tendency to attract electrons than the other.
As a result, electrons are transferred from one material to the other during rubbing.
The material that loses electrons becomes positively charged.
The material that gains electrons becomes negatively charged.
Since the charging is caused by the rubbing action, it is called charging by friction.
This is different from charging by induction or conduction, which do not involve rubbing.
Answer:B. friction