Explanations:Prepositions are essential parts of speech that indicate the relationship between a noun or pronoun and other parts of the sentence. In the context of geography and spatial relationships, prepositions like "between," "among," "for," and "around" are used to describe the position or connection of locations.
The preposition "between" is specifically used to describe the relationship between two distinct points or entities. It implies a direct connection or a space that separates two items. For example, when we say "There is a national highway between Chennai and Bengaluru," we are indicating that the highway directly connects these two cities, with no other cities or points of interest mentioned in the context.
On the other hand, "among" is used when referring to a relationship involving more than two items. For instance, "There are several national highways among the cities of Chennai, Bengaluru, and Hyderabad" would be correct if we were discussing multiple cities. However, since the question only mentions Chennai and Bengaluru, "among" would be incorrect.
The preposition "for" is typically used to indicate purpose or destination, not spatial relationships. For example, "The highway is for connecting Chennai and Bengaluru" would be correct if we were discussing the purpose of the highway, but it does not describe the spatial relationship between the two cities.
Lastly, "around" suggests a circuitous or indirect path, which is not appropriate for describing a direct connection between two specific locations. For example, "The highway goes around Chennai and Bengaluru" would imply a more indirect route, which is not the case here.
Therefore, the correct preposition to use in the context of a national highway connecting two specific cities, Chennai and Bengaluru, is "between."