Which pronoun correctly completes the sentence?

congratulate finished the challenging obstacle course.

a.
whoever

b.
whomever

here's some tricks. write on a book that you have read and really enjoyed. first, start by writing down basic event in the book. have your first paragraph be an intro explaining like the author, the reason the book was written if known, and other backround info like that. paragraph two explain what happens in the first few chapters and the signifigance it had. then for paragraph 3, do the same thing but for the middle. i'm pretty sure you get the point for paragraph 4. just rap things up and explain the call to action. for the final paragragh (paragraph 5) , explain your views on the book, the message, ect. tip: something that might is to go onto cliff notes or something and read the anaylisis of each chapter.

some books i recommend;

diary of anne frank

lord of the flies

i would say the bible, because the bible is true and it gives you hope, happiness, and peace for the future and it gives you answers if you have questions, along with stories, and how the world is going to end