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.
The answer is B. which.
Answer:
a. I am now swimming for an hour.
b. he has been playing this guitar since he was seven years old.
c. how long are they discussing?
d. she's been collecting dolls for 3 years
e. the office has been using this machine since 1997.
Sentence A has a disagreement between "were" (plural) and "no one" (singular).
Sentence B has a disagreement between "was" (singular) and "problems" (plural).
Sentence C, however, has complete agreement between the subject and verb. Therefore, the answer is C.
Potential questions could be on the test...
and about who you are And should you care about what others thinks
And about similarities and differences about peoples identity and if you would change for someone? :)