Explanation
It is not always possible to provide adequate segregation of duties between programming and operations in order to meet certain business requirements. A mitigating control is to record all of the programmers' actions for later review by their supervisor, which would reduce the likelihood of any inappropriate action on the part of the programmer. Choices A, C and D do not solve the problem.

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.
Reference = 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

A change control process is the methodology that ensures that anything that could be impacted by a development change will be reevaluated. Problem management is the general process intended to manage all problems, not those specifically related to security. Background screening is the process to evaluate employee references when they are hired. BIA is the methodology used to evaluate risks in the business continuity process.