When a negative charged rod is brought near, but does not touch, the initially unchanged electroscope shown below, the leaves spring apart `(I)`. When the electroscope is then touched with a finger, the leaves collapse `(II)`. When next the finger and finally the rod are removed, the leaves spring apart a second time `(III)`. The charge on the leaves is

Options

A. positive in both `I` and `III`
B. negative in both `I` and `III`
C. positive in `I`, negative in `III`
D. negative in `I`, positive in `III`

Answer

D

Explanation

Due to induced effect.