How are all humans similar?

Well all humans are similar is some ways.

Explanation:

One way is that we are all human and  we do some thing the same way.

All humans are similar in the aspect that we are all members of the same species. This means we are diverse enough to have certain variable characteristics (E.x. skin color, height, hair/eye color, metabolism), but are also capable of interbreeding with eachother (Any human can interbreed with any human of the opposite biological sex, as long as there are no reproductive obstructions or defects in either partner).

Explanation:

if you listed your answers right then i believe your answer is b.