Which of the Following Best Illustrates the Skills Acquired Though

Which of the following best illustrates the skills acquired though informal learning, rather than formal schooling?

A) Somali children accurately memorize the placement of familiar objects, but make errors in memorizing the placement of unfamiliar objects.
B) Bilingual children accurately address monolingual children in the appropriate language.
C) Street children in Brazil accurately perform mathematical calculations in daily life, but make errors when solving math problems on paper.
D) all of the above