South America can be divided into three physical regions: mountains and highlands, river basins, and coastal plains. Mountains and coastal plains generally run in a north-south direction, while highlands and river basins generally run in an east-west direction.
I would choose to evaluate the effectiveness of the solution. Which would basically mean that you are double checking that the solution is correct
A noble is someone who is a member of the nobility, meaning that they are from a social class that "possesses more acknowledged privileges or eminence, than most classes in a society, membership thereof typically being hereditary." A peasant is defined as "a laborer, a farmer who owns a small farm or other member of a traditional subservient class of rural folk that existed in pre-industrial societies, especially in the Middle Ages under feudalism, and in present times still survive in some pre-industrial societies."