I think the second option is the best (by making the ramps height and length equal) because the first option will require more pushing, the third option will only make the ramp lighter which could cause it to not stay in place, the last option would make it harder to push the boxes up because the rubber will make it harder to slide the boxes up. I hope this helps:)
Explanation:
Depends if the parent is Heterozygous or Homozygous.
It would be the same alleles if the parent was Homozygous and it would be different if the parent was Heterozygous.
Organisms that eat they producers or that don't make their own food
Fungi are responsible for what common human ailment athlete's foot infections