Final answer:
Adding more pulleys to a system increases the mechanical advantage by distributing the load, allowing for the same weight to be lifted with less effort force as the number of supporting rope segments increase.
Step-by-step explanation:
Adding more pulleys to a system affects the mechanical advantage (MA) by increasing it. This is because each pulley in a system adds another length of rope that works in tandem to distribute the load. The mechanical advantage of a pulley system is determined by the number of segments of rope that support the load being lifted. Simply put, if there are more ropes supporting the load due to the addition of pulleys, less effort is needed to lift that load since the weight is distributed across more ropes.
An example of this would be a system where three pulleys are used, and there are effectively three cables attached to the load, creating a situation where the applied force is approximately 3T; thus, the machine has an MA of roughly 3. For a frictionless pulley system, the force output is an integral multiple of the tension in the rope. As such, correct option in regard to the mechanical advantage of a system by adding more pulleys is to increase the mechanical advantage by distributing the load (option c).