By registering a derivative work, an author registers all of the material included in the derivative work, including that which previously appeared in an unregistered, original work created by the author.  So plaintiff’s registration of Chart B which included the elements of Chart A sufficed to obtain a copyright on the elements of Chart A.  Moreover, the author of an original work is entitled to sue a third party who makes an unauthorized copy of a derivative work to the extent that the material copied derived from the underlying work.