A. You need to install the glibc-devel package. It contains the object files necessary for developing programs which use the standard C libraries (which are used by nearly all programs). If you are developing programs which will use the standard C libraries, your system needs to have these standard object files available in order to create the executables.
Install glibc-devel if you are going to develop programs which will use the standard C libraries.
# apt-get install g++-multilib
or
sudo apt-get install libc6-dev-i386