The correct option is D 25
We know,
1.When a resistance is divided into n identical resistances, each of resistance (say R') become Rn.
2.When n identical resistors each of resistance R', are connected in parallel, the equivalent resistance is R′n
The resistor R ,when divided into five parts become resistors of resistance R5each.
The recombination of five resistors, each of resistance R5, gives a resistor of equivalent resistance R' of value R55=R25
Hence,
RR′=251