A Chief Information Security Officer (CISO) is tasked with outsourcing the analysis of security logs. These will need to still be reviewed on a regular basis to ensure the security of the company has

SaaS provides software applications over the cloud but does not specifically cover outsourced managed analysis or monitoring services.

MaaS (Managed as a Service) is specifically designed to outsource the management and analysis of services - such as security log review - to a third party. The provider handles the day-to-day analysis and reporting on a regular basis, which directly meets the requirement of ongoing log review without the organization needing internal resources dedicated to that function.

IaaS provides virtualized infrastructure resources like compute and storage, not outsourced security analysis services.

PaaS provides a platform for developing and deploying applications, not a managed service for ongoing security log analysis.