Mount Everest is not a person, so whom and who cannot be used.
The phrase that the blank spot is in needs a transition word to flow correctly. 'that' does not flow, as it would make this phrase grammatically incorrect.
you can eat healthy and exercise. being mindful will help because you will be able to keep a good health wheel, and you can fix things before they get to bad
It says a "narrative essay" and A makes the most sense. You aren't analyzing, you're not telling a story going place to place. It says "exciting journey" and you don't need to argue about anything.