Which file is used by ld.so to find libraries quickly without actually having to search the director

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.
/var/.cache

C.
/etc/ld.so

D.
/var/ld/cache

E.
/etc/ld.so.conf