The traits of a hero are usually determined by all of these except for C - the plot of the story.
For that reason, the correct answer is probably a - cultural values, b - their experiences, d - their mentors.
It also makes sense that the different traits every hero has are rather complex when compiled together and the reasons why they have become as they have become have multiple reasons.
These lines are called cross-contour lines.
Cross-contour lines are used in making nice pieces of art but most importantly they are a huge helping tool. These cross-contour lines can help people understand the solid form and the appearance of object from different perspectives and vantage points. Thus they are invaluable learning tool.