Table 1: The horizontal pulling forces (F) and resulting acceleration (a) for the cart.
The cart experiences no motion when there is 0.1 N of horizontal force, so F=0 in this case. When one uses Newton's Second Law to find the acceleration caused by each force, it becomes clear that every row in the chart represents a horizontal force of approximately F=20 N. The best fit for the missing value is F=-30N.
The best explanation that best predicts what happens to the trait over time is that the incidence of mid-digital hair will not change because it offers no selective advantage or disadvantage. A mutation is a sudden, spontaneous random change that occurs in the genetic make up of an organism. The presence or absence of mid-digital hair is controlled by a single gene with two alleles, and the allele H is dominant.
I would say C.
I hope this helps.