Explanation: The security accreditation task of the System Development Life Cycle (SDLC) process is completed at the end of the system implementation phase. The SDLC is a framework that describes the stages and activities involved in the development, deployment, and maintenance of a system. The SDLC typically consists of the following phases: system initiation, system acquisition and development, system implementation, system operations and maintenance, and system disposal. The security accreditation task is the process of formally authorizing a system to operate in a specific environment, based on the security requirements, controls, and risks. The security accreditation task is part of the security certification and accreditation (C&A) process, which also includes the security certification task, which is the process of technically evaluating and testing the security controls and functionality of a system. The security accreditation task is completed at the end of the system implementation phase, which is the phase where the system is installed, configured, integrated, and tested in the target environment. The security accreditation task involves reviewing the security certification results and documentation, such as the security plan, the security assessment report, and the plan of action and milestones, and making a risk-based decision to grant, deny, or conditionally grant the authorization to operate (ATO) the system. The security accreditation task is usually performed by a senior official, such as the authorizing official (AO) or the designated approving authority (DAA), who has the authority and responsibility to accept the security risks and approve the system operation. The security accreditation task is not completed at the end of the system acquisition and development, system operations and maintenance, or system initiation phases. The system acquisition and development phase is the phase where the system requirements, design, and development are defined and executed, and the security controls are selected and implemented. The system operations and maintenance phase is the phase where the system is used and supported in the operational environment, and the security controls are monitored and updated. The system initiation phase is the phase where the system concept, scope, and objectives are established, and the security categorization and planning are performed.