ISO/IEC 27001 specifies requirements for which of the following?

ISO/IEC 27001 is an international standard that outlines the requirements for an information security management system (ISMS). This standard provides a systematic approach to managing sensitive company information, ensuring its confidentiality, integrity, and availability.

The main objective of ISO/IEC 27001 is to help organizations manage their information security risks effectively. It establishes a framework for implementing, maintaining, and continually improving the ISMS, which includes policies, processes, and procedures. Organizations that comply with ISO/IEC 27001 can better manage their cybersecurity risks and comply with legal and regulatory requirements related to information security.

The other choices do not align with the focus of ISO/IEC 27001. Data encryption is a specific technical measure that can be part of security management but is not the overarching requirement of the standard. Software testing pertains to quality assurance processes but does not relate to a management system for information security. Environmental management, although important for sustainability, is covered under a different set of standards such as ISO 14001 and is not relevant to ISO/IEC 27001.