Concept:An electroscope is a passive device that detects or tests electric charge, but it never produces charge.
Explanation:An electroscope is used to test the type of charge on a charged body by observing the behaviour of its leaves.
It can also detect ionization in air because ionised air allows the electroscope to discharge.
It detects the presence and approximate amount of charge already present on a body.
However, an electroscope cannot generate or produce electric charge in a body.
Therefore, producing electric charge is not a use of an electroscope.
Answer:Option D: producing electric charge in a body.