The best option to reduce the risk of unauthorized sharing of information during the due diligence process is B). Establishing mutual non-disclosure agreements (NDAs). This is because NDAs are legal contracts that bind the parties to keep confidential any information that is exchanged or disclosed during the due diligence process. NDAs can help to protect the sensitive data, intellectual property, trade secrets, or business strategies of both the organization and the third party from being leaked, stolen, or misused by unauthorized parties.
NDAs can also specify the terms and conditions for the use, storage, and disposal of the information, as well as the consequences for breaching the agreement.
References = CISM Review Manual 15th Edition, Chapter 3, Section 3.2.1, page 1341; CISM Review Questions, Answers & Explanations Manual 9th Edition, Question 70, page 18