Choice A is the correct answer. The y-intercept is the point where the graph crosses the y-axis, which happens when $x = 0$.

1. Substitute $x=0$ into the equation: $y = 0^2 - 5(0) + 6$.
2. Simplify: $y = 6$.
3. The point is $(0, 6)$.

Choice B is incorrect because of a sign error. Choice C is incorrect because it swaps x and y (this would be an x-intercept). Choice D is incorrect because it uses the coefficient $b$.