Really need easy identify the class of the italicized pronoun(s) in the sentence. is percival lowell the astronomer{ whom} we credit for discovering pluto?

To choose a good persuasive essay topic,begin with a big idea,narrow it down,and a.then narrow it down more; it is impossible to have a topic that is too narrow. b.do some research to see what you should write about c.specify-ask a question you want answered in your argument