In the third sentence of the first paragraph, the narrator’s description of Mrs. De Ropp as "those three-fifths of the world that are necessary and disagreeable and real" suggests that Mrs. De Ropp is a sensible individual who earns Conradin’s respect
A. Mrs. De Ropp is a strict person who fails to appreciate Conradin’s creative spirit
B. Mrs. De Ropp has no real understanding of Conradin’s medical condition
C. Conradin, unlike Mrs. De Ropp, views the world through a rational and precise lens
D. Conradin has no understanding of the value system that Mrs. De Ropp upholds

According to big five personality traits which first introduced by A Psychologist named Robert McCrae , 'Disagreeable' refers to the type of personality who tend to prefer a traditional approach when handling situation. They tend to be really reluctant to accept changes and love the 'old strict rules' when handling every sitautions in their life.

This can be seen in Mrs. De Ropp's attitude toward Conradin.

Creative people such as Conrandin tend to be the type of people who constantly seeking new / innovative methods to solve the problems around them. This is the exact opposite of Disagreeable people. This explain why it is hard for Mrs. De Ropp to appreciate Conradin’s creative spirit