What file is read by the program ldconfig?

A.
/lib/ld.so

B.
/etc/ld.so.conf

C.
/etc/ld.so.cache

D.
/etc/modules.conf

Explanation/Reference:
/lib/ld.so is the linux loader and using information collected by ldconfig (especially /etc/ld.so.cache)
/etc/ld.so.cache is one of the outputs of ldconfig.
/etc/modules.conf is an optional configuration file used by the modprobe command.