What was required in order to reprogram the ENIAC computer?

The correct choice highlights the unique operational method of the ENIAC, which was one of the earliest electronic general-purpose computers. To reprogram the ENIAC, operators had to physically configure its wiring. This involved plugging and unplugging a series of cables and cables into different panels to change the connections that determined its functions and operations.

This characteristic of the ENIAC demonstrates how early computers operated without modern software and programming brevity. Programming was extremely hands-on, relying on physical manipulation of hardware rather than written code as we understand today.

While software updates or changes to power supplies and hardware components like the mainframe are common in modern computing, they did not pertain to how the ENIAC was programmed. Instead, its reprogramming was entirely dependent on the physical wiring setup, which highlights a significant evolution in computer engineering and programming methodologies over time.