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

Explanation/Reference:
B) is used by ldconfig to create /etc/ld.so.cache
C) is the program itself
D) does not exist (on fedora or ubuntu)
E) does not exist