I have no clue you should ask Google
Take EDM for example; it's a combination of words and sounds all cramed together to create a piece of music, most of the time it has no official reason or back story but is simply made to be enjoyed. This concept is the same with Jazz music. When jazz was invented there was no definitive reason or way to play it, you just grabbed an instrument and started playing whatever cords and rhythms you thought sounded nice.
Contours are lines on a map that show or represent the height of the land. When contours are closely spaced this means that the land rises rapidly with distance or the land is steep. When they a widely spaced it means the land rises gently or the area is relatively flat or undulating. Specific contour shapes usually represent a particular land form or feature. V shaped contours usually represent a valley or a river valley.
I believe it is b the traditions, cause its based on experience
