The answer is: B
Explanation
The correct option is B: A dozen novels and a number of poetry collections have been authored by the writer who passed away recently.
The sentence "The writer who passed away recently has authored a dozen novels and a number of poetry collections" is in the active voice. To convert it into the passive voice, we need to focus on the objects (the novels and poetry collections) being acted upon and the tense must remain present perfect.
Option B correctly uses the present perfect tense "have been authored" to match the original sentence.
Option A incorrectly uses the simple past tense "were authored," which changes the meaning.
Option C incorrectly uses "has been authored," which does not agree with the plural subjects "a dozen novels and a number of poetry collections."
Option D incorrectly uses the past perfect tense "had been authored," which changes the tense from the original sentence.
So, the complete passive voice sentence is: "A dozen novels and a number of poetry collections have been authored by the writer who passed away recently."