Which type of region do you feel is more common, homogeneous, nodal, or vernacular? why?

Nodal regions are more common than vernacular and homogeneous regions.

Explanation:

First of all, we need to explain all of the concepts to understand the answer.

Homogeneous region: a homogeneous region is a region defined by its physical and geographical means. It has nothing to do with culture or people. Thus, it is the less common of the three because well the world's geography is amazingly different, we have mountains, rivers, flatlands, etc. So, the option is wrong.

Second, the vernacular region is a type or region in which different sites share something in common like an invention, person of interest or vicinity with a singular place and they identify themselves as the same region. This could be very common, however, the answer is incorrect because there is just not as much as the third option.

Third, Nodal region. The nodal region is the type of region composed by a metropolis and smaller different sites that are interconnected and share focal point to their interactions. This is the most common of all because the structure of civilization is built under this model.

a is the answer i believe.

a and b because with the other three, they simplify to something else.