The correct answer is - B. It was a dramatic change in that people now had some control over their environment.
When the people started to perform agriculture, they changed their lifestyle, from hunter-gatherers, to settled farmers. This was a very big change, and people actually for the first time started to have control over the environment of certain places where they settled. They started to change the ecosystem by destroying the grasses, shrubs, and trees along side the big fertile rivers because they needed that soil for agriculture, started to use plants for their own purpose and farm them, and over time select them and make them more productive. They also were able to produce more food than what they needed at the moment, thus having healthy reserves, and also they were able to keep big portion of the animals out of certain areas because they had built houses and fences, as well as having dogs for protection, so the animals were not risking to move in those parts in general.
