What can be done to an internal IC to produce signals that indicate three different voltage levels?

To produce signals that indicate three different voltage levels from an internal integrated circuit (IC), establishing connections between specific pins can be crucial. By shorting between pins other than VCC and ground, you can modify the behavior of the IC, allowing it to output different voltage levels based on how the pins are configured. This method leverages the design of the IC, as many are constructed to respond differently based on their pin connections, effectively creating logic states indicative of multiple voltage levels.

The other options do not facilitate the creation of three voltage levels. Connecting VCC to ground would cause a short circuit, effectively damaging the IC and preventing it from functioning properly. Replacing the entire component does not directly create different voltage levels and would likely just waste time and resources if the current IC could already be adapted. Increasing the input voltage might change the output behavior, but it doesn't inherently create multiple voltage levels unless the IC and its configuration support such behavior. Thus, modifying the connections between pins is the most effective solution in this case.