In cases of double-patenting rejections, what is the purpose of filing a terminal disclaimer?

Filing a terminal disclaimer serves the purpose of allowing related patents to expire at the same time, which is crucial in managing double-patenting rejections. When a patent application faces a double-patenting rejection, it indicates that the claims are not patentably distinct from an earlier-filed patent. By filing a terminal disclaimer, the applicant essentially agrees that the term of the later patent will be limited to that of the earlier patent, ensuring that both patents will have the same expiration date. This aligns the effective patent protection by preventing the holder from extending exclusivity beyond what is allowed for the earlier patent, thus reinforcing the legal framework aimed at maintaining fair competition and preventing unjustly prolonging patent rights.

The other options presented do not accurately reflect the function of a terminal disclaimer. It does not extend the patent term, nor does it ensure that claims do not overlap in a way that tackles the fundamental issue of double patenting. Additionally, it does not alter the ownership of the patent; the disclaimer itself deals solely with the term and relationship of the claims in question.