The body frame takes into consideration the bone structures which vary in size for different people . Also the bone density of one person is different from another. Weight and density of bones determines the size of the body frame. There are three categories of body frames: small, medium and large frame. People with large frames have a bone structure which is much larger, while people with small frames have much lesser bone weight.
It would be your third option. because if you look at the reproductive system both the sperm and the egg carry different amounts of genetic information.
