Question 42If $a,$ $b,$ and $c$ are positive integers, the radicals $\sqrt{a+\dfrac bc}$ and $a\sqrt{\dfrac bc}$ are equal when and only when:$a=b=c=1$$a=b$ and $c=a=1$$c=\dfrac{b(a^2-1)}a$$a=b$ and $c$ is any value$a=b$ and $c=a-1$