Traits controlled by genes can only be acted upon natural selection because they have to helpful to the survival of that organism.
Centimeter = 1/100 of a Meter
Kilometer = 1000 Meters
86,000/100 = 860 Meters
860/1000 = 0.86 Kilometers
Mutualism. e.g. oxpecker and zebra
commensalism. e.g. remora fish and sharks
parasitism. e.g. tapeworms and cow
I believe it is C, but i cant be sure
I hope i helped a little :)