Concept:The first formal schools in the Gold Coast were the castle schools set up by European merchants (Portuguese, Dutch, Danes and British) at forts such as Elmina, Cape Coast and Christiansborg.
Solution:These schools trained Africans and mulatto children to read, write and count so that they could work as clerks, interpreters, storekeepers and agents for the European trading companies.
Literate Africans made communication, record keeping and bargaining between the coastal people and the Europeans easier, so trade between the Gold Coast and Europe grew.
Option B is wrong: schooling did not increase the population. Options C and D: early schooling trained a small number of clerks, not a large labour force, and it taught no farming skills to raise crop production.
Answer:Option A (improvement in foreign trade)