Option 4 ( R2 and R3 ) is the correct answer.
Explanation:
- In the below given diagram, we can see a circuit diagram that has four resistors such as R1, R2, R3, and R4.
- The opening of the circuit is noted as "a" and the ending is noted as "b".
- By observing the above diagram, we can clearly see that R2 and R3 are the pair of resistors that are connected in a parallel manner.
- Where all the other resistors such as R1 and R4 are neither connected in parallel nor in series.
Hence we can conclude that Resistor R2 and R3 are the ones that are connected in parallel.
