Which of these is the Euclidean algorithm step for GCD(a,b)\text{GCD}(a, b)GCD(a,b) where a>ba > ba>b?
a=bq+ra = bq + ra=bq+r
b=aq+rb = aq + rb=aq+r
a=r/ba = r/ba=r/b
a−b=ra - b = ra−b=r