This topic involves the ownership of patent application right for cooperative development. Article 340th of the Contract Law stipulates that unless otherwise agreed by the parties, the right to apply for a patent belongs to the parties involved in cooperative development. If one party transfers its patent application right, under the same conditions, the other parties have the priority to be assigned. If one party to a cooperative development waives its right to apply for a patent, it may apply separately by the other party or jointly by other parties. If the applicant obtains a patent right, the party who gives up the right to apply for a patent may exploit the patent free of charge. If one party to the cooperative development does not agree to apply for a patent, the other party or other parties shall not apply for a patent. Options a, b and c are correct, and option d is wrong, so the answer to this question is D.