What type of rock constitutes the highlands of the moon?

The highlands of the Moon primarily consist of a type of rock called anorthosite. Anorthosite is characterized by its composition, which is largely made up of plagioclase feldspar, a mineral that gives the highlands their light coloration. This rock type forms during the cooling of magma from the Moon's early volcanic activity, leading to the solidification of crystals that primarily consist of plagioclase.

Anorthosite is significant because it not only makes up the majority of the lunar highlands but also represents the oldest terrain on the Moon. The highlands are rugged and heavily cratered, indicating that they have been geologically stable for billions of years.

The other types of rocks mentioned do play roles in lunar geology but do not constitute the highlands specifically. Basalt, for instance, is found in the lunar maria, while lunar rocks is a general term that could refer to various lunar materials. Natural glass can also be found on the Moon, primarily created from the impact events, but it is not a major component of the highland regions. Therefore, anorthosite is the most accurate answer regarding the predominant rock type in the lunar highlands.