Answer:
The correct answer is: reading.
Explanation:
When he was seven years old, Frederick Douglass was given to the brother of his former owner's son‑in‑law, Hugh Auld.
Auld's wife, Sophia Auld, was not accustomed to having slaves and was very kind to Frederick, to the point that she started teaching him how to read.
However, she was forced to stop when her husband found out because he believed that once you start educating slaves, they become "useless" to their masters since a slave should know nothing but to obey.
