Answer:
A. They can be used only to monitor schedules.
Explanation:
CPM and PERT are project management technique and software adapted in the management of projects by an individual or company.
PERT is a project management technique which helps in the planning, scheduling, organising, coordinating and controlling uncertain activities while on the otherhand CPM is a statistical technique of project management in which planning, scheduling, organising, coordination and control of well-defined activities take place.
Both are needed for better control of time and cost associated with any given project.