What is the impact of caffeine as a central nervous system stimulant?

Caffeine, as a central nervous system stimulant, is known to affect the body in ways that can lead to tolerance and withdrawal symptoms among regular users. Over time, with consistent consumption, the body adapts to the presence of caffeine, often resulting in the need for increased amounts to achieve the same stimulating effects. This increase in tolerance can create a cycle where individuals may consume more caffeine than initially intended.

Upon reducing or abruptly stopping caffeine intake, individuals may experience withdrawal symptoms. These can include headaches, fatigue, irritability, and difficulty concentrating, which are clear indications that the body has become accustomed to the stimulant effects of caffeine. This relationship between regular use and subsequent withdrawal highlights the potential for developing a dependency on caffeine, which is why option C is recognized as the most accurate statement regarding the impact of caffeine.

In contrast, the other choices refer to extreme effects or notions that do not align with the well-documented effects of caffeine consumption. Hallucinations are not a typical result of caffeine use, long-term effects do exist, and caffeine can indeed become habit-forming, making those options less valid in the context of understanding caffeine's role as a stimulant.