Final answer:
The quote emphasizes the importance of reading and writing skills by comparing Charlie's learning achievement with a low mental age to that of someone understanding Einstein's theory of relativity without help.
Step-by-step explanation:
The significance of Charlie's achievement, as described in the statement provided, aligns most closely with option 3: It highlights the importance of reading and writing skills.
The comparison made between Charlie's accomplishment in learning to read and write, despite having a low mental age, and the hypothetical scenario of someone learning Einstein's theory of relativity without help, emphasizes the tremendous significance of Charlie's achievement in mastering these fundamental skills. This achievement underscores the crucial importance of literacy—reading and writing skills—regardless of one's cognitive abilities or mental age. It suggests that the ability to read and write is a crucial aspect of personal development and communication, regardless of the individual's intellectual capacity. This comparison draws attention to the value and significance of basic education, highlighting the profound impact it can have on an individual's life, regardless of their cognitive level.