Standard form is Ax+By=C, so with that knowledge, we can work with the problem to get it how we want it!
Our first step is to get x and y on the same side of the equals sign. To do that, we can subtract an x from both sides, turning 6y = x + 5 into -x +6y = 5. Lucky for us, this brings us straight to the answer, which is A) -x +6y = 5!