Answer:
the correct answer is A
Step-by-step explanation:
In an electrical circuit the switch can be of two types: unipolar and bipolar.
The bipolar switch refers to a three-contact switch that allows the polarity in the circuit to be reversed.
The unipolar switch has only two contacts so the polarity of the circuit is in one direction and the switch serves to interrupt the passage of electrons in the circuit.
Consequently the correct answer is A