Why were houses constructed so closely together in early nucleated settlements?
a. to maximize arable land
b. to provide protection
c. to allow neighbors to rely on each other
d. to provide equal access to water sources

The correct answer is letter D. To provide equal access to water sources. Nucleated settlements are designed to be like this to enable people to have easy access not only on water but also in other forms of produce like agriculture and domestication. This gives people the equal opportunity to maximize what available resources are within their location.