Answer:
A. Okonkwo is upset that Nwoye has joined the missionaries because he thinks that proves that Nwoye is weak and effeminate.
Step-by-step explanation:
In the book Things Fall Apart, we learn that the character of Okonkwo is obsessed with being strong and masculine, because he believes that his father's weakness was a tragedy for his family. However, Okonkwo's son Nwoye is a sensitive, caring man, and Okonkwo sees this as a weakness. When Nwoye joins the missionaries, Okonkwo sees this as evidence of Nwoye's weakness, and becomes very upset.