According to the PMBOK® Guide, specifically the Project Schedule Management knowledge area, there is a defined sequence of six processes required to ensure the timely completion of a project.

Plan Schedule Management: Establishing the policies, procedures, and documentation for planning, developing, managing, executing, and controlling the project schedule.

Define Activities: Identifying and documenting the specific actions to be performed to produce the project deliverables.

Sequence Activities: Identifying and documenting relationships (dependencies) among the project activities.

Estimate Activity Durations: Estimating the number of work periods needed to complete individual activities with estimated resources.

Develop Schedule: Analyzing activity sequences, durations, resource requirements, and schedule constraints to create the project schedule model for project execution and monitoring.

Control Schedule: The ongoing process of monitoring the status of project activities to update project progress and manage changes to the schedule baseline to achieve the plan.

Analysis of other options:

A. Define Quality of Activities: This is not a standard process in Schedule Management. Quality considerations are managed within Project Quality Management.

C. Estimate Cost of Activities: This process belongs to Project Cost Management, not Schedule Management. While costs and schedules are linked, they are distinct knowledge areas with separate processes.

D. Combined Errors: This option incorrectly includes both " Define Quality of Activities " and " Estimate Cost of Activities, " and it also omits the critical " Plan Schedule Management " and " Control Schedule " processes.

Per PMI standards, effective schedule management requires the full lifecycle from Planning through Developing to Controlling to ensure the project remains on track.