(c) The plastic tube is attached to a metal mast. This would cause the metal mast to become positively charged.
Explain why there is a wire connecting the metal mast to the Earth.

can someone please help by answering the question and not write anything ​

Explanation:

Since the mast is a conductor and connected to the plastic so charge transfer takes place between the mast and the tube because the mast is connected to the ground with wire which is called grounded which means its potential is 0 equal to the ground so that charge can transfer from plastic tube to the ground. This is why the wire is used to connect the metal mast to the Earth.