A direct result of the production of an agricultural surplus in early civilizations was the:

The production of an agricultural surplus in early civilizations led to the specialization of labor and increased economic complexity because when a society produces more food than is necessary for survival, it enables people to engage in activities beyond subsistence farming. With surplus food, not everyone in the society needs to devote their time to agriculture, allowing individuals to focus on other skills and professions such as crafting, trade, governance, and religious leadership.

This specialization fosters an economy where different roles and trades emerge, facilitating the growth of towns and cities. As various groups within the society began developing distinct skills, they could trade with one another, creating a more intricate economic system. This transition marks one of the key characteristics of early civilizations, as it is closely linked to social stratification and the establishment of complex societal structures and institutions.

Considering the other options, while the development of organized religious beliefs may have occurred during this time, it wasn't a direct result of agricultural surplus. Similarly, while agricultural advancements may have impacted nomadic societies or led to communal legal codes, these developments are not the primary or direct outcomes of having an agricultural surplus. Rather, the increased economic complexity and specialization of labor are the most immediate and direct consequences of such surpluses in early civilizations.