What Was One of the Main Purposes of the Well-Field

What was one of the main purposes of the well-field reform that resulted in regular reallocation of land every few years during the Tang Dynasty?

A) To ensure good land for the nobility.
B) To ensure good land for the peasants.
C) To make allowance for changes in the population distribution.
D) To tame the influx of foreign landed nobility.
E) To make sure the tenant peasants would remain on the land and produce food for urban workers.