Obviously BOTH.because without fossil-fuels we would not have agriculture because fertilizers consist of fossil-fuels for its nitrogenization. Also, currently, we cannot survive without fossil-fuels/crude oil because the planet will experience “ENERGY POVERTY” that can collapse global economies eventually. Now a soldiers gloves, boots, helmet, sunglasses, backpack, pretty much everything he carries is a direct partial byproduct or an indirect byproduct (indirect meaning oil was needed to manufacture/produce). Okay so the fuel consumption alone should give you an idea of how needed oil is.
Agriculture, fueled literally by fossil fuels for tractors, plows, reapers, sprayers, fertilizers, harvesters and combines, trucks and trains, graineries and processing plants and pumps and cleaners and canneries and bottle washers and trucks and ovens and warehouses and shippers, is feeding 6.5 billion people. Every day. 6.5 billion people. Some 6 billion of those will starve to in the cold and dark if fossilfuels are restricted.
I think both agriculture and oil are important in their place but if they are compared then agriculture will be considered as the most important thing. This is because agriculture has been with man since birth when nothing else existed except agriculture. Oil has been a very short time since the world started to develop, after that oil reserves started to be discovered and various facilities and conveniences for man started to be created by its use.
When there was no oil, man was still alive, He used wood as fuel. When there were no vehicles, people traveled on foot and various animals were used to carry goods. Airplanes, trains, military equipment, various industries, modern needs were nothing, life was difficult but not impossible, because there was no oil, but still there was agriculture and the greatest need. In olden times, soldiers did not have modern equipment but war was still fought, Even then there was no oil but still agriculture was there and was considered the most important need of the time. I think even today agriculture is the need of the hour.