Final answer:
Lucy sees caring for her nephew as a major educational influence because it contributed to her personal growth and gave her new insights into responsibility and family dynamics. This experience was formative in her youth and likely enhanced her emotional and intellectual development. Option number a is correct.
Step-by-step explanation:
Lucy describes caring for her nephew as "one of the best educating influences of my youth" because it provided her with an opportunity to learn about responsibility, personal development, and family dynamics.
This experience likely exposed her to new challenges and learning experiences that greatly contributed to her personal growth, enhancing her understanding of the world, and preparing her for future roles in life, possibly including parenting. While the question does not specify which aspects of education Lucy found most impactful, it is likely that the experience contributed to her emotional and intellectual development as well as a greater appreciation for family and education.