I assume the previous thread you are referring to is this one?
If so, yes, the answer you were given is b), and it is the correct answer.
Why do you think the answer you were given in the previous thread is wrong? If it's because of this...
...then it's not a valid reason, because the answer to the question just quoted is "no". A "purely Newtonian" approach will give incorrect answers unless you are at a radial coordinate r that is much, much larger than the Schwarzschild radius (2M), so that the error in the Newtonian formulas becomes too small to measure.