First person point of view is mostly talking about yourself, meanwhile in a story there will be a lot of I's. Like, "I love the game." "I like candy." First person point of view is yourself.
Yes. He saw them has a subject (he), a verb (saw), and an object (them), so it is totally a sentence.
B - too specific for the purpose
While that would be a good topic sentence, it is far too specific for the thesis of an entire essay
