How to solve this question?​

multiple allele inheritance is traits controlled by more than 2 alleles (ex: pigeons having 3 alleles of one gene govern their feather color).

electric field is a function of 1/r^2

yes, the force per unit charge for a point charge is inverse square law.

3. dark matter

empty space could also be a simple vacuum

one "light year" is the distance that light travels, through vacuum, in one julian year.   that's 365.25 days, of 24 hours each.