Final answer:
The most direct result of excess crop production was increased trade, since it led to a surplus that was often sold off, raising the volume of trade despite causing lower crop prices.
Step-by-step explanation:
The correct answer to the question of which was most directly a result of excess crop production is D. Increased trade. When there was an overproduction of crops, especially during post-war times and periods of rapid agricultural advancement, it often led to a surplus that needed to be sold, which in turn increased trade. However, while excess crop production did indeed increase the volume of trade, it also led to a drop in crop prices due to the over-saturation of the market. In turn, this pushed down the value of agricultural products causing economic issues for farmers, but increased trade remains the most direct result of the given options.