Step 1: Understanding "core" instruments.
The UN recognizes nine core international human rights treaties, which include CRC, ICCPR, and CEDAW.
Step 2: Checking the given options.
(a) CRC — core treaty.
(b) ICCPR — core treaty.
(c) CEDAW — core treaty.
(d) Genocide Convention — important, but primarily an international criminal law treaty, not part of the nine core HR treaties.
\[
\boxed{(d)}
\]