The right answer is "C. A peasant boy waits in the forest to escape with the king's daughter and wonders if his love is strong enough to keep her happy.
"
The explanation for this is that the peasant has a complex plot so, that there is his growth and development as a character and that is a characteristic of round characters.
Plain characters are two-dimensional because they are relatively simple and do not change over the course of a job. In contrast, round characters are complex and undergoing development, sometimes enough to surprise the reader.
