Which file is used by ld.so to find libraries quickly without actually having to search the directoriesin its library path?

Which file is used by ld.so to find libraries quickly without actually having to search the directories
in its library path?

A.
/etc/ld.so.cache

B.
/etc/ld.so.conf

C.
/etc/ld.so

D.
/var/ld/cache

E.
/var/.cache