Final answer:
The correct answer is option c. Jack London's phrase "Nature was not kindly to the flesh" emphasizes the harshness of nature, following naturalistic themes where nature is often indifferent or hostile to human beings.
Step-by-step explanation:
The phrase "Nature was not kindly to the flesh" is an example of the author's perspective because London emphasizes the harshness of nature. This line reflects naturalistic themes prominent in the works of authors like Jack London, where nature is often depicted as indifferent or hostile, and human beings face a struggle against natural forces that are beyond their control. London's use of literary naturalism showcases characters who experience the indifference of nature, emphasizing the power and sometimes the cruelty of natural elements as they impact human life.
In taking this perspective, London's work does not criticize human adaptability per se but focuses on the external environment's overwhelming force that can overpower even the most determined human effort. The struggle of man versus nature, such as venturing out into the cold with only a dog, is less about criticizing humans than accentuating the sheer brutal challenge that nature poses.