The primary concern when negotiating a contract for a hot site is the availability of the site in the event of multiple disaster declarations. A hot site is a fully equipped alternative facility that can be used to resume business operations in the event of a disaster. However, if multiple clients of the hot site provider declare a disaster at the same time, there may be a shortage of resources or capacity to accommodate all of them.
Therefore, the contract should specify the terms and conditions for ensuring the availability and priority of the hot site for the organization. The other options are not as important as availability, as they do not affect the ability to use the hot site in a disaster situation. Coordination with the site staff in the event of multiple disaster declarations is a logistical issue that can be resolved by communication and planning. Reciprocal agreements with other organizations are alternative arrangements that can be used to share resources or facilities in a disaster, but they may not be as reliable or suitable as a hot site. Complete testing of the recovery plan is a good practice that can help validate and improve the effectiveness of the recovery plan, but it is not a concern for negotiating a contract for a hot site. References: CISA Review Manual (Digital Version), Chapter 4, Section 4.2.3

The change management process is the set of procedures and activities that ensure that changes to the information system are authorized, tested, documented, and implemented in a controlled manner12. A defect in a recent release indicates that there may be issues with the quality assurance, testing, or approval of the changes, which could affect the reliability, security, and performance of the system3 . Therefore, the auditor's next step should be to evaluate the change management process and identify the root cause of the defect, as well as the impact and remediation of the incident.
References
1: Change Management - CISA
2: What is Change Management? - Definition from Techopedia
3: How to Audit Change Management - ISACA Journal
The Business Case for Security | CISA

Discovery sampling is an appropriate sampling method for an IS auditor who intends to launch an intensive investigation if one exception is found. Discovery sampling is a type of attribute sampling that determines the sample size based on an acceptable risk of not finding at least one occurrence of an attribute when a given rate of occurrence exists in a population. Discovery sampling can be used by an IS auditor who wants to detect fraud or errors that have a low probability but high impacton an audit objective. The other options are not appropriate sampling methods for this purpose, as they may involve judgmental sampling, variable sampling, or stratified sampling. References:
* CISA Review Manual (Digital Version), Chapter 2, Section 2.31
* CISA ReviewQuestions, Answers & Explanations Database, Question ID 230