5.1 Each Receiving Party shall, on receipt of written demand from the Disclosing Party destroy or, at the option of the Disclosing Party, return all original and copy documents, samples, prototypes and other information containing Confidential Information provided to it or its Related Persons pursuant to this letter which is in the possession or control of the Receiving Party or its Related Persons, provided that the Receiving Party and its Related Persons may retain: