重听内容：“When you look at the other planets, especially the planets in the outer solar system, where Pluto orbits. you see that Pluto stand outs. It's the outer ball, and I'll give you one guess why” （我自己听写的，没有原文，不一定全对）
what does the professor mean when he says this :"and I'll give you one guess why"?
A He thinks the question is difficult to answer.
B He thinks the reason is obvious.
When you look at the other planets, especially the planets in the outer solar system, where Pluto orbits. you see that Pluto stand outs. It's the outer ball, and I'll give you one guess why
根据你给的题目来看，因为前面给出了详细的解释，然后让同学们猜一个啥或者解释一个啥，所以理解答案那应该是显而易见的