Why is A greater than B? Requirements on the test paper title? There won't be such obvious contradictions in the test paper, will there?

If we only talk about the requirements of an ellipse, when a > b, the focus of the ellipse is on the X axis, when a < b, the focus of the ellipse is on the Y axis, and when a=b, the ellipse becomes a circle.

So if the title doesn't say a > b, as far as the ellipse itself is concerned, a < b is completely acceptable. This just makes the focus of the ellipse on the y axis.