The main purpose of adding capacitors to a circuit is to:

Adding capacitors to a circuit primarily serves to stabilize the power factor, which is a crucial aspect in electrical systems, especially in industrial and commercial settings. The power factor is a measure of how effectively electrical power is being converted into useful work output. A low power factor indicates poor efficiency, where more apparent power is required to achieve the same amount of real power.

When capacitors are introduced, they provide reactive power (VARs) to the system, which compensates for the inductive loads that often contribute to a lagging power factor. By doing this, capacitors help improve the overall power factor, leading to reduced losses in the electrical system, potential cost savings on energy bills, and increased capacity for additional loads without requiring an upgrade to the electrical infrastructure.

In contrast, increasing energy demand, reducing current flow, and enhancing safety measures do not directly relate to the primary function of capacitors in power systems. While capacitors may indirectly influence overall current flow by improving efficiency, their main role is to address power factor issues, making stabilization of the power factor the correct purpose associated with capacitor use in circuits.