Three lamps are in circuit as shown in figure. At what condition 100 W lamp will have the maximum brightness?

A

Key $$K_1$$ is open, $$K_2$$ is closed and $$K_3$$ is open

B

$$K_1$$ is closed, $$K_2$$ is open and $$K_3$$ is also open

C

Both (a) and (b)

D

Key $$K_1$$ is closed, $$K_2$$ is open and $$K_3$$ is closed