It's D. The verb 'buy' is transitive as it takes a DO.
Answer:
Thank you :)
Many people feel like insecure and they belittle themselves and I want to thank you for reminding people that we're all good at something. Your words had a great impact on me especially since I feel like I'm the worst at math :)
(I am People Smart, Self Smart, Nature Smart, and Word Smart)
I believe it is D because the allies weren't formed yet before war broke out but when it did, that's when the allies were formed.