The first two sentences say that both A and B are straight lines of plane α, and the straight line L intersects with A at point A and B at point B. If A and B are two different points, then the straight line L and plane α have two different intersections, so it must be on plane α. But the title doesn't say that A and B don't coincide. Item c is exactly the same as the title condition.

However, according to the test center, the proposer means to test knowledge point A.