Final answer:
Starting with x equal to 1, after the operation x -= 1, the new value of x will be 0. The operation is a subtraction assignment, subtracting 1 from the current value of x.
Step-by-step explanation:
If x is 1 and then you use the operation x -= 1, you're performing a subtraction assignment, which means you subtract 1 from the current value of x and then assign the result back to x. The operation is equivalent to x = x - 1. Therefore, starting with x equal to 1, after subtracting 1, the new value of x will be 0. So, the correct answer is b. 0.