Answer:
The incidence of mid-digital hair will not change because it offers no selective advantage or disadvantage.
Step-by-step explanation:
The traits of an organism are determined by the genes of an organism. In the given question, the trait is the hair growth on the middle digit or finger which is passed on to the generation but in some, it is expressed and in some, it is not.
This trait does not provide any benefit to the humans neither they are disadvantageous and thus is the neutral trait. Therefore, this trait will not change over time.
Thus, the selected option is correct.