The output is half of the input

An output function is a function that an optimization function calls at each iteration of its algorithm. Typically, you might use an output function to generate graphical output, record the history of the data the algorithm generates, or halt the algorithm based on the data at the current iteration. The output is also the letter that that represents the equation. For example, y= 3x+2, the (y=) is the output.

The answer is b: step 2.