Question: A Very Harold & Kumar 3D Christmas is part of what series?
Facts:
David Krumholtz played as Seth Goldstein in A Very Harold & Kumar 3D Christmas
A Very Harold &amp; Kumar 3D Christmas is a sequel to Harold &  Kumar Go to White Castle
Harold & Kumar Go to White Castle is a 2004 American stoner comedy film
Harold & Kumar Go to White Castle was the first installment of the "Harold &amp; Kumar" series.
Answer: the "Harold & Kumar" series.