In this task, you are given a multiple-choice question and you have to pick the correct option. Answer with option indexes (i.e., "A", "B", "C", and "D").
Q: Lisa was hiking in a rocky area and in a rock, she saw what looked like footprints made by a bird. But weirdly, they were in a rock. Where did they come from? (A) The footprints were originally in mud or peat, but after a lot of time, the substance had been changed into rock (B) The rock was actually an asteroid (C) a very heavy bird made imprints in the rock. (D) a spaceship used a laser to make the etches in the rock
A:
A