Final answer:
The integrated circuit on the IR board is also known as a microchip, which is a small silicon chip containing a complex assembly of electronic components.
Step-by-step explanation:
The part on the IR board that is an integrated circuit is typically referred to as a microchip. An integrated circuit is a complex assembly of a multitude of electronic components, such as transistors, resistors, and capacitors, all etched onto a small piece of silicon. It is designed to perform a wide array of functions within electronic devices, including processing, memory storage, and logic operations. This type of circuitry is at the core of modern technology, enabling the miniaturization of components and the creation of powerful, compact devices like computers and cell phones. Therefore, the correct answer is d) Microchip.