There are 20 cows and 10 farmers in a field. What is the ratio of the number of ears to the number of legs in the field, and what is the significance of this ratio?
A. 2:3, because two-thirds of those in the field are cows, and they have the greater share of ears and legs
B. 3:5, because for every 3 ears present in the field, there are 5 legs present
C. 2:3, because each farmer has two-thirds the number of ears and legs that a cow has
D. 3:5, because on average, there are 3 ears per individual and 5 legs per individual in the field