As a wave travels through a medium, it displaces the particle perpendicular to the motion of the wave. We can conclude that this is a

this allows people to make the best decision or pursue the best option. when alternatives are weighed using their advantages and disadvantages, the option whose disadvantages outweigh the advantages (based on a qualitative or quantitative analysis) are shunned while those whose advantages outweigh their disadvantages are pursued.  

mistakes are ok