Final answer:
The process of converting program code into instructions that a board understands is called compiling. This is crucial in programming for microcontrollers and is the step before uploading the code to the board.
Step-by-step explanation:
Before a program "code" can be uploaded to a board, such as an Arduino or other microcontroller, it must be translated into a format that the microcontroller can understand. This process is known as compiling. When you compile code, you transform the human-readable source code written in a high-level programming language into machine code, which consists of binary instructions specific to the processor's architecture. In the context of the given options, the correct answer to what this process is called is Compile, corresponding to option 3).