Final answer:
Passages from Chapter 7 of 'The Story of My Life' suggest that Miss Sullivan was a transformative teacher for Helen Keller, marking her life's division into two distinct parts and reflecting a significant positive influence.
Thus, the correct option is a.
Step-by-step explanation:
In "The Story of My Life," Chapter 7, supports the idea that Miss Sullivan is a gifted and effective teacher through various passages. The specific passages that demonstrate her effectiveness are not explicitly provided in the information given, however, we can infer from Helen Keller's own words in the text: "The most important day I remember in all my life is the one on which my teacher, Anne Mansfield Sullivan, came to me."
This passage highlights the transformative impact Miss Sullivan had on Keller's life. The immeasurable contrasts between Keller's life before and after Sullivan's arrival suggests a significant positive influence imparted by Sullivan's teaching.
Additionally, the text indicates that the introduction to the narrative sketches boundaries signifying a clear before and after Anne Sullivan's arrival, marking a turning point and separation into two distinct parts of Keller's life. These remarks make it evident that Miss Sullivan's role as Keller's teacher was paramount to her development and achievements.
Therefore, the correct option is A. A and B