Final answer:
Paul talks about himself in Galatians to emphasize his authority as an apostle, not to boast or criticize others. His personal experiences are meant to validate his teachings and establish credibility as a teacher of true Christian doctrine. The correct option is a.
Step-by-step explanation:
The reason Paul spends much of the first two chapters of Galatians talking about himself is to emphasize his authority as an apostle. This is done to validate his teachings to the Galatians and establish credibility since he was not one of the original disciples of Jesus, and his apostleship was sometimes questioned. Contrary to options such as boasting about his accomplishments or criticizing other apostles, Paul's recounting of his personal experiences serves to demonstrate that his authority and message come directly from Jesus Christ and not from human instruction or his past life as a persecutor of Christians.
Furthermore, his self-discussion helps to counter the claims of other teachers who were attempting to sway the Galatians into following a different version of the gospel. By sharing his personal transformation and the direct revelation he received from Jesus, Paul strengthens the position that his teachings are consistent with divine will and the true message of Christianity. At a time when early Christians were divided on significant issues and interpretations of Jesus's teachings, Paul's assertion becomes vital in promoting unity and orthodoxy within the young Christian communities.