According to the Textbook, Which One of the Following Conclusions

According to the textbook, which one of the following conclusions is most warranted from research on brain development?

A) To become truly skilled in such domains as art and music, children should begin systematic instruction in these domains before the age of five.
B) The ability to think abstractly depends on the development of many synaptic connections during the first five years of life.
C) Children probably won't acquire the basic skills essential to succeed in the adult world
D) Classroom experiences can significantly enhance people's cognitive development throughout the elementary, secondary, and post-secondary school years.
E) g., reading, writing, math) unless they begin developing those skills in the early elementary grades at the latest.