According to anthropologists, the use of human language covers a wide spectrum from practical communication between people engaged in the same task to establishing hierarchy within a social group.

A practical communication between people engaged in the same task to establishing hierarchy

B communicating practically between people engaging in the same task to the establishment of hierarchy

C practical communication between people engaged in the same task to the establishing of hierarchy

D communicating practically between people engaging in the same task to hierarchy established

E practical communication between people engaged in the same task to the establishment of hierarchy

OA is E

Query :

I have seen examples of the type

THE X and THE Y
THE X and Y

However, here MGMAT says that it is OK to have

X and THE Y

How is it possible? Can some1 throw some light on this please

[spoiler]E) CORRECT. This choice correctly changes Y to a regular noun phrase "the establishment of hierarchy," so that this phrase is now parallel to X, "practical communication." It is not necessary that both phrases have the article "the."[/spoiler]