Which of these is the best thesis for an essay analyzing an author's writing style?

a) he often wrote about the lingering effects of combat experience on those who lived it
b) his personal experience provided him with plenty of ideas for characters and plots
c) his use of descriptive details and figurative language brings the chaotic, brutal reality of war to life for the reader.
d) he won a pulitzer prize for his work as a journalist before he began writing fiction.