1) which pronoun correctly completes the sentence?
was chosen for the job?
a) whom
b) who
2) which pronoun correctly completes the sentence?
to was the poem dedicated?
a) who
b) whom

1. B
2. B
The word who can only be used when it is the subject of a verb

Whom is never the subject of a verb. 

For the first question, the correct answer among the choices given is option B. The sentence would be "Who was chosen for the job?". For the second question, the correct answer is option B. The complete sentence would be "To whom was the poem dedicated?".