Question 13Given the binary operation $*$ defined by $a*b=a^b$ for all positive numbers $a$ and $b.$ Then for all positive $a,$ $b,$ $c,$ $n,$ we have:$a*b=b*a$$a*(b*c)=(a*b)*c$$a*(b^n)=(a*n)*b$$(a*b)^n=a*(bn)$None of these