Franz Kafka wrote the metamorphosis at first because <u>he felt the need to express the confrontation of man with the oppression of a modern world</u> (At that time it was the outbreak of the First World War), and as such the history of metamorphosis originated as a story about the unbearable weight of responsibility he had to express that feeling.
Explanation:
Franz Kafka was a writer born in Prague, his works and writings were influential in existentialism, the philosophy of the absurd and other literary currents.
He also directly influenced writers who read his works thanks tohis crude, unusual and absurd style.
I feel as if B helps explain the conflict more. Whereas the other answers are just details or add ons in the short story. Also the other answers seem more external than B.