Very Small Mercury Batteries Have Been Made and Used in a Multitude

Multiple Choice

Very small mercury batteries have been made and used in a multitude of applications.Why have they been replaced by other kinds of batteries for most applications?

A) Mercury has become far too expensive to use in batteries.
B) Mercury is poisonous and difficult to dispose of.
C) These batteries cannot generate enough current for any modern devices.
D) Though they may be made very small,they are far too heavy to use in most applications.